thunderbolt: Runtime resume USB4 port when retimers are scanned

Sometimes when plugging in a USB4 device we might see following error:

  thunderbolt 1-0:3.1: runtime PM trying to activate child device 1-0:3.1 but parent (usb4_port3) is not active

This happens because the parent USB4 port was still runtime suspended.
Fix this by runtime resuming the USB4 port before scanning the retimers
below it.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>