media: v4l2_core: Add p_area to struct v4l2_ext_control

Allow accessing V4L2_CTRL_TYPE_AREA controls without any casting.
Signed-off-by: Ricardo Ribalda Delgado <ribalda@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

include/uapi/linux/videodev2.h

@@ -1684,6 +1684,7 @@ struct v4l2_ext_control {
 		__u8 __user *p_u8;
 		__u16 __user *p_u16;
 		__u32 __user *p_u32;
+		struct v4l2_area __user *p_area;
 		void __user *ptr;
 	};
 } __attribute__ ((packed));