rockpi-s: bump u-boot v2024.10 -> v2026.07 (build on trixie hosts)

u-boot v2024.10 fails to build on Debian trixie hosts: the pre-generated
scripts/dtc/pylibfdt/libfdt_wrap.c is incompatible with trixie's SWIG 4.3
("too few arguments to function 'SWIG_Python_AppendOutput'"), so scripts_dtc
dies and the uboot artifact never builds.

Bump to v2026.07, matching luckfox-rk3308b-nova which already builds the same
rk3308 SoC on this u-boot tag — so the SoC is supported and the pylibfdt wrapper
is SWIG-4.3-clean. rockpi-s has no board-specific u-boot patches, keeps its own
rock-pi-s-rk3308_defconfig, uart0 DDR blob, BL31 and binman scenario; the shared
v2026.07 patchdir's board_luckfox-* patches are board-scoped, so rockpi-s won't
pick them up.

Needs an on-target boot check (uart0 console, RAM).

Signed-off-by: Igor Pecovnik <igor@armbian.com>

Author: igorpecovnik

config/boards/rockpi-s.conf

@@ -17,8 +17,8 @@ SERIALCON="ttyS0"
 MODULES_BLACKLIST="rockchipdrm analogix_dp dw_mipi_dsi dw_hdmi gpu_sched lima hantro_vpu panfrost"
 HAS_VIDEO_OUTPUT="no"
 
-BOOTBRANCH_BOARD="tag:v2024.10"
-BOOTPATCHDIR="v2024.10"
+BOOTBRANCH_BOARD="tag:v2026.07-rc4"
+BOOTPATCHDIR="v2026.07"
 BOOT_SCENARIO="binman"
 DDR_BLOB="rk33/rk3308_ddr_589MHz_uart0_m0_v2.07.bin"
 BL31_BLOB="rk33/rk3308_bl31_v2.26.elf"