crypto: qat - change type for ctx_mask

Change type for ctx_mask from unsigned char to unsigned long to avoid
type casting.

Signed-off-by: Jack Xu <jack.xu@intel.com>
Co-developed-by: Wojciech Ziemba <wojciech.ziemba@intel.com>
Signed-off-by: Wojciech Ziemba <wojciech.ziemba@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>