lib/crypto: mips/sha1: Migrate optimized code into library

lib/crypto: mips/sha1: Migrate optimized code into library

Instead of exposing the mips-optimized SHA-1 code via mips-specific
crypto_shash algorithms, instead just implement the sha1_blocks()
library function.  This is much simpler, it makes the SHA-1 library
functions be mips-optimized, and it fixes the longstanding issue where
the mips-optimized SHA-1 code was disabled by default.  SHA-1 still
remains available through crypto_shash, but individual architectures no
longer need to handle it.

Note: to see the diff from arch/mips/cavium-octeon/crypto/octeon-sha1.c
to lib/crypto/mips/sha1.h, view this commit with 'git show -M10'.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250712232329.818226-10-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>