usb: dwc3: Do not initiate remote wakeup from core layer

commit c36d8e94 ("usb: dwc3: gadget: put link to U0
before Start Transfer") forcing remote wakeup even if
it is not supported by function. In case remote wakeup
fails it goes ahead and issues start transfer cmd, which
defeats the purpose of the change. Function driver needs
to make the decision if device needs to perform remote
wakeup or not by calling usb_gadget_wakeup (in HS mode) or
usb_func_wakeup (in SS or higher mode).

Change-Id: I7ec5a29ae5beb1ea501f4127f440074396db9bda
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>