x86/platform/uv: Update MMIOH references based on new UV5 MMRs

Make modifications to the MMIOH mappings to accommodate changes for UV5.

[ Fix W=1 build warnings. ]
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Mike Travis <mike.travis@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Link: https://lkml.kernel.org/r/20201005203929.148656-8-mike.travis@hpe.com