crypto: ccp - Fix handling of RSA exponent on a v5 device

The exponent size in the ccp_op structure is in bits. A v5
CCP requires the exponent size to be in bytes, so convert
the size from bits to bytes when populating the descriptor.

The current code references the exponent in memory, but
these fields have not been set since the exponent is
actually store in the LSB. Populate the descriptor with
the LSB location (address).

Signed-off-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>