Ignore this kernel in "pmbootstrap kconfig check" by default, so we can
use the upstream kernel config without any changes. But still enable the
kernel config check again.
The related pmbootstrap change will be merged soon:
https://gitlab.com/postmarketOS/pmbootstrap/merge_requests/1753
[skip ci]: this change doesn't affect the build
Do not replace compiler-gcc.h. This is necessary now, as we are
replacing compiler-gcc.h by default again, as it is needed for most
kernels. Not increasing the pkgrel to avoid unnecessary rebuild, I have
verified that this works.
NOTE: in the last commit message, I wrote about OVERWRITE_GCC=0. But
the variable is called REPLACE_GCC, as I've decided to rename it before
submitting. I forgot to change it in the commit message.
[skip ci]: this kernel takes more than one hour to build, so it won't
finish in CI.
