MAINTAINERS: Assume ov8856 driver maintainership

Dongchun's e-mail address is no longer valid, assign the ov8856 driver to
myself.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

MAINTAINERS

@@ -15481,7 +15481,7 @@ F:	Documentation/devicetree/bindings/media/i2c/ov7740.txt
 F:	drivers/media/i2c/ov7740.c
 
 OMNIVISION OV8856 SENSOR DRIVER
-M:	Dongchun Zhu <dongchun.zhu@mediatek.com>
+M:	Sakari Ailus <sakari.ailus@linux.intel.com>
 L:	linux-media@vger.kernel.org
 S:	Maintained
 T:	git git://linuxtv.org/media_tree.git