x86, uv, uv3: Update Hub Info for SGI UV3

This patch updates the UV HUB info for UV3.  The "is_uv3_hub" and
"is_uvx_hub" (UV2 or UV3) functions are added as well as the addresses
and sizes of the MMR regions for UV3.

Signed-off-by: Mike Travis <travis@sgi.com>
Link: http://lkml.kernel.org/r/20130211194508.610723192@gulag1.americas.sgi.com
Acked-by: Russ Anderson <rja@sgi.com>
Reviewed-by: Dimitri Sivanich <sivanich@sgi.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>