dwc3: gadget: Improve remote wakeup functionality

Current available remote wakeup functionality is not robust
enough as most of time it failed to wait for host to complete
resuming signle and move USB device to U0 state. Hence enhance
this functionality by using link state change interrupt and
waiting for max 16 sec for host to resume.

Change-Id: I375d7812336ce0ecc49bfeea859bc76d90a4e0b9
Signed-off-by: Mayank Rana <mrana@codeaurora.org>