xhci: Switch Intel Lynx Point ports to EHCI on shutdown.

The same issue like with Panther Point chipsets. If the USB ports are
switched to xHCI on shutdown, the xHCI host will send a spurious interrupt,
which will wake the system. Some BIOS have work around for this, but not all.
One example is Compulab's mini-desktop, the Intense-PC2.

The bug can be avoided if the USB ports are switched back to EHCI on
shutdown.

This patch should be backported to stable kernels as old as 3.12,
that contain the commit 638298d
"xhci: Fix spurious wakeups after S5 on Haswell"

Signed-off-by: Denis Turischev <denis@compulab.co.il>
Cc: stable@vger.kernel.org
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-pci.c

@@ -134,6 +134,8 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
 		 */
 		if (pdev->subsystem_vendor == PCI_VENDOR_ID_HP)
 			xhci->quirks |= XHCI_SPURIOUS_WAKEUP;
+
+		xhci->quirks |= XHCI_SPURIOUS_REBOOT;
 	}
 	if (pdev->vendor == PCI_VENDOR_ID_ETRON &&
 			pdev->device == PCI_DEVICE_ID_ASROCK_P67) {