crypto: caam - fix rfc3686(ctr(aes)) IV load

-nonce is being loaded using append_load_imm_u32() instead of
append_load_as_imm() (nonce is a byte array / stream, not a 4-byte
variable)
-counter is not being added in big endian format, as mandatated by
RFC3686 and expected by the crypto engine

Signed-off-by: Catalin Vasile <cata.vasile@nxp.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>