dm: usb: gadget: Fix boot breakage on sunxi platforms

Fixes commit 013116243950 ("dm: usb: create a new UCLASS ID for USB gadget
devices")

The UCLASS_DRIVER for id UCLASS_USB_GADGET_GENERIC needs to be declared
even for platforms that do not enable DM_USB_GADGET. Otherwise the driver
for their usb peripheral controller fails to bind.

Reported-by: Priit Laes <plaes@plaes.org>
Reported-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Tested-by: Priit Laes <plaes@plaes.org>
Acked-by: Jagan Teki <jagan@openedev.com>
diff --git a/drivers/usb/gadget/udc/Makefile b/drivers/usb/gadget/udc/Makefile
index 38ac2dd..95dbf0c 100644
--- a/drivers/usb/gadget/udc/Makefile
+++ b/drivers/usb/gadget/udc/Makefile
@@ -6,4 +6,5 @@
 obj-$(CONFIG_USB_DWC3_GADGET)	+= udc-core.o
 endif
 
-obj-$(CONFIG_$(SPL_)DM_USB_GADGET)	+= udc-uclass.o udc-core.o
+obj-$(CONFIG_$(SPL_)DM_USB_GADGET)	+= udc-core.o
+obj-$(CONFIG_$(SPL_)DM) += udc-uclass.o