IntelFsp2WrapperPkg: Fix constant if statements issue

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1351

Internal code quality scanning found 2 constant if
statements related to FixedPcdGet8 () usage.
Since the PCD can be PatchableInModule too, it should be
changed to PcdGet8 () to fix this issue.

Test: Verified on internal platform and booted successfully.

Cc: Jiewen Yao <Jiewen.yao@intel.com>
Cc: Desimone Nathaniel L <nathaniel.l.desimone@intel.com>
Cc: Wu Hao A <hao.a.wu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Chasel Chiu <chasel.chiu@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Hao Wu <hao.a.wu@intel.com>