Currently most of the assembly files that use architecture extensions
enable them using the .arch directive but crc32.S uses .cpu instead. Move
that over to .arch for consistency.

Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20200414182843.31664-1-broonie@kernel.org


Signed-off-by: Will Deacon <will@kernel.org>