powerpc/crc-t10dif: expose CRC-T10DIF function through lib

powerpc/crc-t10dif: expose CRC-T10DIF function through lib

Move the powerpc CRC-T10DIF assembly code into the lib directory and
wire it up to the library interface.  This allows it to be used without
going through the crypto API.  It remains usable via the crypto API too
via the shash algorithms that use the library interface.  Thus all the
arch-specific "shash" code becomes unnecessary and is removed.

Note: to see the diff from arch/powerpc/crypto/crct10dif-vpmsum_glue.c
to arch/powerpc/lib/crc-t10dif-glue.c, view this commit with
'git show -M10'.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20241202012056.209768-8-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>