Existing code forgot to set Descriptor->SpecificFlag to 0 when
the resource type is non-prefetchable MMIO.
The patch adds the missing assignment.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>