crypto: caam - treat SGT address pointer as u64

Even for i.MX, CAAM is able to use address pointers greater than
32 bits, the address pointer field being interpreted as a double word.
Enforce u64 address pointer in the sec4_sg_entry struct.

This patch fixes the SGT address pointer endianness issue for
32bit platforms where core endianness != caam endianness.

Signed-off-by: Tudor Ambarus <tudor-dan.ambarus@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>