eal: introduce bit operations API

Bitwise operation APIs are defined and used in a lot of PMDs,
which caused a huge code duplication. To reduce duplication,
this patch consolidates them into a common API family.

Signed-off-by: Joyce Kong <joyce.kong@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Phil Yang <phil.yang@arm.com>
Acked-by: Morten Brørup <mb@smartsharesystems.com>