usb: host: xhci-plat: create shared hcd after having added main hcd

usb: host: xhci-plat: create shared hcd after having added main hcd

This patch is in preparation of an extension where in case of a
root hub with no ports no shared hcd will be created.
Whether one of the root hubs has no ports we figure our in
usb_add_hcd() for the primary hcd. Therefore create the shared hcd
only after this call.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20220511220450.85367-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>