usb: gadget: Handle remote_wakeup during RESET

In some cases host may reset BUS instead of RESUME. If there is any
pending request in rw_queue then driver adding this request to the rw_queue
and marks the remote wakeup pending flag to true and resume the bus.
In resume, the pending requests from remote wakeup queue are pushed
to the hardware and clears remote wakeup pending flag. But In reset case
this request may never get cleared and rw_pending flag is never cleared.
Due to this enumeration failures are seen during suspend/resume testing.

This patch adds the changes to handle this in reset path. Now driver
is calling purge_rw_queue to clear the remote wakeup pending flag
from reset handler.

Change-Id: Ifd696eaad7d6832bef8ccff743955c2ae8bc7988
Signed-off-by: ChandanaKishori Chiluveru <cchilu@codeaurora.org>