usb: dwc3: gadget: pass dep as argument to endpoint command

In all call sites of dwc3_send_gadget_ep_cmd() we
already had a valid dep pointer, so instead of
passing dwc and dep->number, which would be used to
fetch the same pointer we already had, just pass dep
directly.

In other words, we're changing:

	struct dwc3_ep *dep = dwc[dep->number];

to just passing struct dwc3_ep *dep as argument.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>