The elf_check_arch() function is also used to test compatibility of
usermode binaries. Kernel modules may have more specific requirements,
for example powerpc would like to test for ABI version compatibility.

Add a weak module_elf_check_arch() that defaults to true, and call it
from elf_validity_check().
Signed-off-by: NJessica Yu <jeyu@kernel.org>
[np: added changelog, adjust name, rebase]
Acked-by: NLuis Chamberlain <mcgrof@kernel.org>
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221128041539.1742489-2-npiggin@gmail.com