MAINTAINERS: Add Zhihao Cheng as UBI/UBIFS reviewer

Recognizing Zhihao Cheng's valuable contributions,
let's officially appoint him as a UBI/UBIFS reviewer.
His demonstrated expertise and assistance make him a valuable
addition to the MTD community.

Cc: Zhihao Cheng <chengzhihao1@huawei.com>
Acked-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

MAINTAINERS

@@ -22471,6 +22471,7 @@ F:	include/uapi/misc/uacce/
 
 UBI FILE SYSTEM (UBIFS)
 M:	Richard Weinberger <richard@nod.at>
+R:	Zhihao Cheng <chengzhihao1@huawei.com>
 L:	linux-mtd@lists.infradead.org
 S:	Supported
 W:	http://www.linux-mtd.infradead.org/doc/ubifs.html
@@ -22599,6 +22600,7 @@ F:	drivers/ufs/host/ufs-renesas.c
 
 UNSORTED BLOCK IMAGES (UBI)
 M:	Richard Weinberger <richard@nod.at>
+R:	Zhihao Cheng <chengzhihao1@huawei.com>
 L:	linux-mtd@lists.infradead.org
 S:	Supported
 W:	http://www.linux-mtd.infradead.org/