Prefix the PowerPC SHA-1 functions with "powerpc_sha1_" rather than
"sha1_".  This allows us to rename the library function sha_init() to
sha1_init() without causing a naming collision.

Cc: linuxppc-dev@lists.ozlabs.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>