usb: dwc2: gadget: Add functionality to exit from LPM L1 state

Add a function which will be called if device is in L1 sleep state
and Resume/Remote Wakeup Detected interrupt is asserted.

Signed-off-by: Sevak Arakelyan <sevaka@synopsys.com>
Signed-off-by: Grigor Tovmasyan <tovmasya@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>