USB: gadget: Implement remote wakeup in ci13xxx_udc

This patch adds support for remote wakeup.  The following things
are handled:

- Process SET_FEATURE/CLEAR_FEATURE control requests sent by host
for enabling/disabling remote wakeup feature.
- Report remote wakeup enable status in response to GET_STATUS
control request.
- Implement wakeup method defined in usb_gadget_ops for initiating
remote wakeup.
- Notify gadget driver about suspend and resume.

Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>