crypto: arm/ghash - Move NEON GHASH assembly into its own file

crypto: arm/ghash - Move NEON GHASH assembly into its own file

arch/arm/crypto/ghash-ce-core.S implements pmull_ghash_update_p8(),
which is used only by a crypto_shash implementation of GHASH.  It also
implements other functions, including pmull_ghash_update_p64() and
others, which are used only by a crypto_aead implementation of AES-GCM.

While some code is shared between pmull_ghash_update_p8() and
pmull_ghash_update_p64(), it's not very much.  Since
pmull_ghash_update_p8() will also need to be migrated into lib/crypto/
to achieve parity in the standalone GHASH support, let's move it into a
separate file ghash-neon-core.S.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260319061723.1140720-7-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>