mmc: bfin_sdh: Update blackfin sd driver email in MAINTAINERS.

Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

MAINTAINERS

@@ -1513,7 +1513,7 @@ S:	Supported
 F:	drivers/rtc/rtc-bfin.c
 
 BLACKFIN SDH DRIVER
-M:	Cliff Cai <cliff.cai@analog.com>
+M:	Sonic Zhang <sonic.zhang@analog.com>
 L:	uclinux-dist-devel@blackfin.uclinux.org
 W:	http://blackfin.uclinux.org
 S:	Supported