xhci: export two xhci_hub functions for xhci-pci module usage

some Intel Alder Lake xHC hosts on ChromeOS platforms need special
workarounds touching port registers at xHC pci host hibernate.

Export xhci_port_state_to_neutral() and xhci_find_slot_id_by_port()
so they can be called from xhci-pci.c and thus the xhci-pci module.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20221130091944.2171610-4-mathias.nyman@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>