usb: gadget: udc: renesas_usb3: fix for no-data control transfer

When bRequestType & USB_DIR_IN is false and req.length is 0 in control
transfer, since it means non-data, this driver should not set the mode
as control write. So, this patch fixes it.

Fixes: 746bfe63 ("usb: gadget: renesas_usb3: add support for Renesas USB3.0 peripheral controller")
Cc: <stable@vger.kernel.org> # v4.5+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>