usb: f_gsi: Implement remote wakeup feature for gsi for bus suspend

Earlier remote wakeup feature for gsi was only available for
function suspend. This change adds remote wakeup feature even
for bus suspend. The entire implementation of remote wakeup
for gsi is now moved to gsi driver from func_ep_queue present
in composite.

Change-Id: I773ea038f1ee7c081c50388db3f3d397fa7e28ba
Signed-off-by: Rohith Kollalsi <rkollals@codeaurora.org>