usb: dwc2: exit hibernation on session request

Controller enters hibernation through suspend interrupt on
disconnection. On connection, session request interrupt is generated.
dwc2 must exit hibernation and restore state from this interrupt
before continuing.

In host mode, exit from hibernation is handled by bus_resume function.

Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@intel.com>
Signed-off-by: Gregory Herrero <gregory.herrero@intel.com>
Tested-by: Robert Baldyga <r.baldyga@samsung.com>
Tested-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Tested-by: John Youn <johnyoun@synopsys.com>
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>