usb: gadget: libcomposite: move composite.c into libcomposite

This moves composite.c into libcomposite and updates all gadgets.
Finally!

Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/gmidi.c b/drivers/usb/gadget/gmidi.c
index 59621ef..4181524 100644
--- a/drivers/usb/gadget/gmidi.c
+++ b/drivers/usb/gadget/gmidi.c
@@ -30,13 +30,13 @@
 #include <sound/rawmidi.h>
 
 #include <linux/usb/ch9.h>
+#include <linux/usb/composite.h>
 #include <linux/usb/gadget.h>
 #include <linux/usb/audio.h>
 #include <linux/usb/midi.h>
 
 #include "gadget_chips.h"
 
-#include "composite.c"
 #include "f_midi.c"
 
 /*-------------------------------------------------------------------------*/