[media] Add missing slab.h to fix linux-next compile errors

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/radio/radio-trust.c b/drivers/media/radio/radio-trust.c
index 0703a80..26a8c60 100644
--- a/drivers/media/radio/radio-trust.c
+++ b/drivers/media/radio/radio-trust.c
@@ -21,6 +21,7 @@
 #include <linux/ioport.h>
 #include <linux/videodev2.h>
 #include <linux/io.h>
+#include <linux/slab.h>
 #include <media/v4l2-device.h>
 #include <media/v4l2-ioctl.h>
 #include "radio-isa.h"