linux_rpi3: fix build failure due to wrong Kconfig
Because of NixOS's generate-config.pl tries to answer 'M' to as much
configs as possible, this exposes the wrong Kconfig in the RPi-specific
code which is added in the new kernel tree intended to support RPi 5.
Add kernel patches to fix the Kconfig, which results in the relavant
part being disabled on the RPi 3 build of the kernel.