video: meson: Drop unnecessary header includes

These files should not be included in meson header files. Drop them and
tidy up the affected C files.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>

include/video.h

@@ -17,6 +17,8 @@
 
 #include <stdio_dev.h>
 
+struct udevice;
+
 struct video_uc_platdata {
 	uint align;
 	uint size;