usb: gadget: Add support for multiple android gadgets

This change enhances the android gadget to support more than one
android device. Implemented in order to support HSIC/HSUSB concurrent
mode.

This feature allows to fully run two compositions concurrently on the
HSUSB and HSIC USB cores, besides the following two restrictions:
1. Cannot run some function driver, for example rmnet, both on HSUSB
   and HSIC concurrently. Each composition should have a different set
   of function drivers.
2. Mass storage can only run on the primary HSUSB core.

Change-Id: I3f57cd237c0499cb6776c17d660bed82be852697
Signed-off-by: Ido Shayevitz <idos@codeaurora.org>
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index d35d861..86c0e73 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -1625,7 +1625,7 @@
 {
 	int retval;
 
-	if (!driver || !driver->dev || !bind || composite)
+	if (!driver || !driver->dev || !bind)
 		return -EINVAL;
 
 	if (!driver->name)