V4L/DVB (4261): Included required header for in-kernel compilation

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/pvrusb2/pvrusb2-v4l2.c

@@ -21,6 +21,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/version.h>
 #include "pvrusb2-context.h"
 #include "pvrusb2-hdw.h"
 #include "pvrusb2.h"