usb: dwc: Fix function wakeup during suspend on SW path

When the SW wants to start USB traffic during USB bus suspend state, it
needs to issue remote-wakeup signaling to the USB host before sending the
function wakeup notification. This patch changes the function wakeup
sending notification function to check whenter the USB bus is suspended
and issue remote-wakeup if needed.

CRs-Fixed: 678203
Change-Id: I1b09e7763c821a0a0e62095b4dc1c8621a2316b3
Signed-off-by: Danny Segal <dsegal@codeaurora.org>