FIX MinPlatformPkg PCIE Base typecasting error.

PCIE Base Address is 64bit PCD and the Mem Limit UINT64.
so typecasting to 32bit is not needed.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4068



Cc: Ray Ni <ray.ni@intel.com>
Cc: Rangasai V Chaganty <rangasai.v.chaganty@intel.com>
Cc: Isaac Oram <isaac.w.oram@intel.com>
Cc: Chasel Chiu <chasel.chiu@intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Isaac Oram <isaac.w.oram@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Eric Dong <eric.dong@intel.com>
Signed-off-by: Ashraf Ali S <ashraf.ali.s@intel.com>
Reviewed-by: Isaac Oram <isaac.w.oram@intel.com>