usb: gadget: rndis: convert into module

In order to convert to configfs the usb functions need to be converted
to a new interface and compiled as modules. This patch creates an rndis
module which will be used by the new functions. After all users of
f_rndis are converted to the new interface, this module can be
merged with f_rndis module.

Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/ether.c

@@ -91,6 +91,8 @@ static inline bool has_rndis(void)
 #endif
 }
 
+#include <linux/module.h>
+
 /*-------------------------------------------------------------------------*/
 
 /*
@@ -104,7 +106,7 @@ static inline bool has_rndis(void)
 #include "f_subset.c"
 #ifdef	USB_ETH_RNDIS
 #include "f_rndis.c"
-#include "rndis.c"
+#include "rndis.h"
 #endif
 #include "f_eem.c"