Move U0 link state handing to USB3 and USB2 specific functions

Note that
bus_state->resuming_ports:
bus_state->resume_done[]:
are only used for USB2, and don't need to cleared for USB3 ports

No functional changes
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>