Add support for `--with-libavcodec=yes` switch with Picodrive

[SineSwiper]

Picodrive can support MP3 playback, often found in Sega CD ZIPs. However, it requires a special configure switch: --with-libavcodec=yes. The setup script could detect that the library exists and add this switch in.

For that matter, there doesn't appear to be any process to customize the compilation route, despite the completely non-standard install process. So, I'm either compiling from the menu without any customizations, or I'm compiling from the actual source, and left trying to figure out how to jam this binary into the Retroarch core directories.

[cmitu]

The libretro core doesn't use configure for compilation and neither does the RetroPie installation script. While better methods exist for compression nowadays (i.e CHD is supported by the core), we can add support for MP3 audio.

The compilation options added by the RetroPie setup script are below. If you can tell which options need to be passed to make or create a pull request with the modifications, then we can include the needed changes in RetroPie's libretro core.

RetroPie-Setup/scriptmodules/libretrocores/lr-picodrive.sh

Lines 24 to 36 in 24ad8fe

	function build_lr-picodrive() {
	local params=()
	if isPlatform "arm"; then
	params+=(platform=armv ARM_ASM=1 use_fame=0 use_cyclone=1 use_sh2drc=1 use_svpdrc=1)
	if isPlatform "armv6"; then
	params+=(use_cz80=0 use_drz80=1)
	else
	params+=(use_cz80=1 use_drz80=0)
	fi
	elif isPlatform "aarch64"; then
	params+=(use_sh2drc=0)
	fi
	make clean