UIO: Add a MAINTAINERS entry for Userspace I/O

This patch adds an entry for the Userspace I/O framework to MAINTAINERS.
Signed-off-by: Hans J. Koch <hjk@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

MAINTAINERS

@@ -4054,6 +4054,14 @@ L:	user-mode-linux-user@lists.sourceforge.net
 W:	http://user-mode-linux.sourceforge.net
 S:	Maintained
 
+USERSPACE I/O (UIO)
+P:	Hans J. Koch
+M:	hjk@linutronix.de
+P:	Greg Kroah-Hartman
+M:	gregkh@suse.de
+L:	linux-kernel@vger.kernel.org
+S:	Maintained
+
 FAT/VFAT/MSDOS FILESYSTEM:
 P:	OGAWA Hirofumi
 M:	hirofumi@mail.parknet.co.jp