lib/crypto: arm64/sha1: Migrate optimized code into library

lib/crypto: arm64/sha1: Migrate optimized code into library

Instead of exposing the arm64-optimized SHA-1 code via arm64-specific
crypto_shash algorithms, instead just implement the sha1_blocks()
library function.  This is much simpler, it makes the SHA-1 library
functions be arm64-optimized, and it fixes the longstanding issue where
the arm64-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.

Remove support for SHA-1 finalization from assembly code, since the
library does not yet support architecture-specific overrides of the
finalization.  (Support for that has been omitted for now, for
simplicity and because usually it isn't performance-critical.)

To match sha1_blocks(), change the type of the nblocks parameter and the
return value of __sha1_ce_transform() from int to size_t.  Update the
assembly code accordingly.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250712232329.818226-9-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>