Add descriptor field offset and mask definition. It is used to parse
FDIR Rx descriptor field value.
Signed-off-by: Yahui Cao <yahui.cao@intel.com> Signed-off-by: Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com> Signed-off-by: Qi Zhang <qi.z.zhang@intel.com> Acked-by: Qiming Yang <qiming.yang@intel.com>