usb: hub: Move hub_port_disable() to fix warning if PM is disabled
If CONFIG_PM=n:
drivers/usb/core/hub.c:107: warning: ‘hub_usb3_port_prepare_disable’ declared inline after being called
drivers/usb/core/hub.c:107: warning: previous declaration of ‘hub_usb3_port_prepare_disable’ was here
To fix this, move hub_port_disable() after
hub_usb3_port_prepare_disable(), and adjust forward declarations.