Move the arm64 implementations of SHA-3 and POLYVAL to the newly introduced scoped ksimd API, which replaces kernel_neon_begin() and kernel_neon_end(). On arm64, this is needed because the latter API will change in an incompatible manner. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Eric Biggers <ebiggers@kernel.org>