Lakka-v6.1: Add LakkaSimpleClock libretoro core for Date & Time adjustment

[ShigeakiAsai]

This PR adds LakkaSimpleClock libretoro core for the system Date & Time adjustment

"Lakka is a lightweight Linux distribution that transforms a small computer into a full blown game console."
The frontend retroarch of Lakka has no function of Date & Time adjustment.
This LakkaSimpleClock libretoro core adds to support Date & Time adjustment function.
And it also adds "Date & Time" into Lakka setting menu on Lakka frontend.

Note.
Nintendo Switch port can't set date and time, please see the following [Restriction].

[Function]

• retroarch
  • Adds "Date & Time" menu into Settings - Services menu on Lakka frontend.
    When this menu item is selected by user, retroarch starts LakkaSimpleClock libretoro core immediately.
  
• LakkaSimpleClock libretoro core
  • This core shows analog time and degital date and time.
    
  • When network is active, this core does not permit edit date and time.
    Because avoid conflicts with NTP time synchronization.
  • When network is inactive, this core permits edit date and time.
    The edit mode is enabled by "START" button push on your controller.
  - In edit mode, You can change the year, month, day, hour, minute, and second using the directional keys. Changes are reflected in the system immediately. Therefore, no confirmation or other actions are required. If you finished edit mode, please push "START" button again. - If you want to exit, please push "SELECT" button.

[Build]

All devices build are passed with no failure
# [Allwinner]
- DISTRO=Lakka PROJECT=Allwinner DEVICE=A64 ARCH=aarch64 make image
- DISTRO=Lakka PROJECT=Allwinner DEVICE=H2-plus ARCH=arm make image
- DISTRO=Lakka PROJECT=Allwinner DEVICE=H3 ARCH=arm make image
- DISTRO=Lakka PROJECT=Allwinner DEVICE=H5 ARCH=aarch64 make image
- DISTRO=Lakka PROJECT=Allwinner DEVICE=H6 ARCH=aarch64 make image
- DISTRO=Lakka PROJECT=Allwinner DEVICE=R40 ARCH=arm make image
# [Amlogic]
- DISTRO=Lakka PROJECT=Amlogic DEVICE=AMLGX ARCH=aarch64 make image
# [Ayn]
- DISTRO=Lakka PROJECT=Ayn DEVICE=Odin ARCH=aarch64 make image
# [Generic]
- DISTRO=Lakka PROJECT=Generic DEVICE=Generic ARCH=i386 make image
- DISTRO=Lakka PROJECT=Generic DEVICE=Generic ARCH=x86_64 make image
- DISTRO=Lakka PROJECT=Generic DEVICE=wayland ARCH=x86_64 make image
- DISTRO=Lakka PROJECT=Generic DEVICE=x11 ARCH=x86_64 make image
# [Nintendo-Switch]
- DISTRO=Lakka PROJECT=L4T DEVICE=Switch ARCH=aarch64 make image
# [NXP]
- DISTRO=Lakka PROJECT=NXP DEVICE=iMX6 ARCH=arm make image
- DISTRO=Lakka PROJECT=NXP DEVICE=iMX8 ARCH=aarch64 make image
# [RPi]
- DISTRO=Lakka PROJECT=RPi DEVICE=RPi ARCH=arm make image
- DISTRO=Lakka PROJECT=RPi DEVICE=RPi2 ARCH=arm make image
- DISTRO=Lakka PROJECT=RPi DEVICE=RPi3 ARCH=aarch64 make image
- DISTRO=Lakka PROJECT=RPi DEVICE=RPi3-Composite ARCH=aarch64 make image
- DISTRO=Lakka PROJECT=RPi DEVICE=RPi4 ARCH=aarch64 make image
- DISTRO=Lakka PROJECT=RPi DEVICE=RPi4-Composite ARCH=aarch64 make image
- DISTRO=Lakka PROJECT=RPi DEVICE=RPi4-GPiCase2 ARCH=aarch64 make image
- DISTRO=Lakka PROJECT=RPi DEVICE=RPi4-PiBoyDmg ARCH=aarch64 make image
- DISTRO=Lakka PROJECT=RPi DEVICE=RPi4-RetroDreamer ARCH=aarch64 make image
- DISTRO=Lakka PROJECT=RPi DEVICE=RPi5 ARCH=aarch64 make image
- DISTRO=Lakka PROJECT=RPi DEVICE=RPi5-Composite ARCH=aarch64 make image
- DISTRO=Lakka PROJECT=RPi DEVICE=RPiZero-GPiCase ARCH=arm make image
- DISTRO=Lakka PROJECT=RPi DEVICE=RPiZero2-GPiCase ARCH=arm make image
- DISTRO=Lakka PROJECT=RPi DEVICE=RPiZero2-GPiCase2W ARCH=aarch64 make image
# [Rockchip]
- DISTRO=Lakka PROJECT=Rockchip DEVICE=RK3288 ARCH=arm make image
- DISTRO=Lakka PROJECT=Rockchip DEVICE=RK3326 ARCH=aarch64 make image
- DISTRO=Lakka PROJECT=Rockchip DEVICE=RK3328 ARCH=aarch64 make image
- DISTRO=Lakka PROJECT=Rockchip DEVICE=RK3399 ARCH=aarch64 make image
# [Samsung]
- DISTRO=Lakka PROJECT=Samsung DEVICE=Exynos ARCH=arm make image

[Test]

a) retroarch is able to start
b) LakkaSimpleClock is able to start via retroarch "Date & Time" menu
c) it detects network online/offline
d) it changes edit mode when push "START" button on controller
e) it is able to change date and time when edit mode
f) LakkaSimpleClock is able to exit by push "SELECT" button on controller
g) chaned date & time is set in Lakkasystem

• AMLGX.aarch64(bananapi-m5)
• Generic.x86_64(intel N100)
• Switch.aarch64 <=== There is restriction for this device support.
• RPi2.arm
• RPi4.aarch64
• RPi5.aarch64
• RK3288.arm(ASUS Tinker board R2.0)
• RK3326.aarch64(ODROID-GO Super)
• Exynos.arm(ODROID-XU4)

[Restriction]

• Switch port can't set date and time.
  I will look into it, but there is a possibility that I may not be able to help.

Thanks
ASAI, Shigeaki