usb: gadget: Call function resume irrespective of speed

In a case when a function is not function suspended
and device entered suspend state in Superspeed mode,
the function will not be resumed when device exits suspend
stae because of the speed check. If a function is
not function suspended it should resumed when the device
exits suspend state.
Fix this by calling the function's resume callback
irrespective of the speed.
Note that the individual function should retain the
USB3.0 function suspend state throughout the device
suspend entry and exit process.

Change-Id: I816eebe7ea0674e63faee6287efeb5ed9fa24395
Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org>