UPSTREAM: crypto: arm64/chacha - fix hchacha_block_neon() for big endian

On big endian arm64 kernels, the xchacha20-neon and xchacha12-neon
self-tests fail because hchacha_block_neon() outputs little endian words
but the C code expects native endianness.  Fix it to output the words in
native endianness (which also makes it match the arm32 version).

Fixes: cc7cf991e9eb ("crypto: arm64/chacha20 - add XChaCha20 support")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
(cherry picked from commit f86d17e9efe010b894db231329ee36b24bcc1b24)
Bug: 152722841
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Change-Id: I5a74cfd06508ed4ab6202282ce28a481fdb07641