crypto: caam - Add definition of rd/wr_reg64 for little endian platform

CAAM IP has certain 64 bit registers . 32 bit architectures cannot force
atomic-64 operations.  This patch adds definition of these atomic-64
operations for little endian platforms. The definitions which existed
previously were for big endian platforms.

Signed-off-by: Ruchika Gupta <ruchika.gupta@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>