usb: f_gsi: Send Function Suspend state to GSI EP OP for suspend

We need to skip checking for link state being in U3
when we receive a Function Suspend. Pass in this information
to GSI EP OP that checks if we are good to suspend channels
with IPA. We skip the check for U3 if we are handling Function
Suspend and check for U3 when we are handling Bus Suspend.

CRs-Fixed: 966352
Change-Id: I29ee0326edbe33b02884495ddc89484bef21e7e0
Signed-off-by: Devdutt Patnaik <dpatnaik@codeaurora.org>