usb: gadget: FunctionFS: create utility file

A header file to be used by f_fs.c and g_ffs.c will be required when
f_fs.c is converted into a module.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index 91b94b1..c0b4cf8 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -27,6 +27,7 @@
 #include <linux/usb/composite.h>
 #include <linux/usb/functionfs.h>
 
+#include "u_fs.h"
 
 #define FUNCTIONFS_MAGIC	0xa647361 /* Chosen by a honest dice roll ;) */