media: v4l2_fh.h: add missing kconfig.h include

v4l2_fh.h uses the IS_ENABLED() macro and thus should include kconfig.h.
Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

include/media/v4l2-fh.h

@@ -22,6 +22,7 @@
 #define V4L2_FH_H
 
 #include <linux/fs.h>
+#include <linux/kconfig.h>
 #include <linux/list.h>
 #include <linux/videodev2.h>