usb: gadget: f_gps: Add support for remote wakeup

The exisiting driver does not notify the host when
there are notifications available with the modem if
the function is selectively suspended (USB 3.0) or
if the device is suspended (USB 2.0).
Add support to notify host by initiating remote wakeup
when there are notifications available with the modem.

Change-Id: Iff7ebf1c196aa58dd32a73ce2c0e66c8587ad9c3
Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org>