kgdb: add documentation

Add in the kgdb documentation for kgdb.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/MAINTAINERS b/MAINTAINERS
index e467758..3eceebb 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2319,6 +2319,12 @@
 L:	kexec@lists.infradead.org
 S:	Maintained
 
+KGDB
+P:	Jason Wessel
+M:	jason.wessel@windriver.com
+L:	kgdb-bugreport@lists.sourceforge.net
+S:	Maintained
+
 KPROBES
 P:	Ananth N Mavinakayanahalli
 M:	ananth@in.ibm.com