rockchip: px30/rk3326: migrate to OF_UPSTREAM

rockchip: px30/rk3326: migrate to OF_UPSTREAM

Migrate PX30/RK3326 boards that exists in Linux v6.8 to use OF_UPSTREAM.

firefly-px30 is not migrated to OF_UPSTREAM because there's no Device
Tree in the Linux kernel.

Differences between U-Boot's Odroid-Go2 and Linux's are now moved to the
-u-boot.dtsi, though I have a gut feeling that the existing cru
overrides aren't necessary (anymore?).

The U-Boot GPIO led-0 is on GPIO0_C1 but such is the pin of PWM3 which
is used for Linux's PWM led-2 so keep Linux's.

I also doubt vcc_cam is actually used, though the Odroid-Go2 Black
Edition uses this dcdc regulator for WiFi, so let's just move it to the
-u-boot.dtsi to play it safe.

Signed-off-by: Quentin Schulz <quentin.schulz@cherry.de>