media: v4l2-tpg: use __u16 instead of int for struct tpg_rbg_color16

Despite the struct says "color16", it was actually using 32 bits
for each color. Fix it.
Suggested-by: Hans Verkuil <hverkuil@xs4all.nl>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

include/media/tpg/v4l2-tpg.h

@@ -32,7 +32,7 @@ struct tpg_rbg_color8 {
 };
 
 struct tpg_rbg_color16 {
-	int r, g, b;
+	__u16 r, g, b;
 };
 
 enum tpg_color {