sgi-xp: setup the notify GRU message queue

Setup the notify GRU message queue that is used for sending user messages
on UV systems.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>