MAINTAINERS: add me as a maintainer of UBI

Add me for UBI custodian.

Signed-off-by: Heiko Schocher <hs@denx.de>
Acked-by: Stefan Roese <sr@denx.de>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index c8386ab..f7a1723 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -390,6 +390,7 @@
 
 UBI
 M:	Kyungmin Park <kmpark@infradead.org>
+M:	Heiko Schocher <hs@denx.de>
 S:	Maintained
 T:	git git://git.denx.de/u-boot-ubi.git
 F:	drivers/mtd/ubi/