MAINTAINERS: add maintainers for GRU, XPC, XPNET and XP

Add MAINTAINERS for GRU, XPNET, XPC and XP drivers.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS

@@ -3754,6 +3754,16 @@ L:	linux-visws-devel@lists.sf.net
 W:	http://linux-visws.sf.net
 S:	Maintained for 2.6.
 
+SGI GRU DRIVER
+P:	Jack Steiner
+M:	steiner@sgi.com
+S:	Maintained
+
+SGI XP/XPC/XPNET DRIVER
+P:	Dean Nelson
+M:	dcn@sgi.com
+S:	Maintained
+
 SIMTEC EB110ATX (Chalice CATS)
 P:	Ben Dooks
 P:	Vincent Sanders