update sn2 maintainer

Now that I'm no longer at SGI and don't have access to Altix equipment, it's time to pass on the job of patch monkey to someone else. Greg Edwards has foolishly^Wkindly volunteered for the job, so here's a patch to update the MAINTAINERS file with the appropriate information.

Jesse

diff -Naurp linux-2.6.12-rc4.orig/MAINTAINERS linux-2.6.12-rc4/MAINTAINERS
@@ -1023,8 +1023,8 @@ W:	http://www.ia64-linux.org/
 S:	Maintained
 
 SN-IA64 (Itanium) SUB-PLATFORM
-P:	Jesse Barnes
-M:	[email protected]
+P:	Greg Edwards
+M:	[email protected]
 L:	[email protected]
 L:	[email protected]
 W:	http://www.sgi.com/altix