usb: host: xhci-plat: omit shared hcd if either root hub has no ports

Activate the just added extension for xhci-plat and omit the shared
hcd if either of the root hubs has no ports.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20220511220450.85367-6-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-plat.c

@@ -245,6 +245,8 @@ static int xhci_plat_probe(struct platform_device *pdev)
 
 	xhci = hcd_to_xhci(hcd);
 
+	xhci->allow_single_roothub = 1;
+
 	/*
 	 * Not all platforms have clks so it is not an error if the
 	 * clock do not exist.