usb: xhci: check usb2 port capabilities before adding hw link PM support

Hardware link powermanagement in usb2 is a per-port capability.
Previously support for hw lpm was enabled for all ports if any usb2 port supported it.

Now instead cache the capability values and check them for each port individually

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

drivers/usb/host/xhci.h

@@ -1532,6 +1532,9 @@ struct xhci_hcd {
 	unsigned		sw_lpm_support:1;
 	/* support xHCI 1.0 spec USB2 hardware LPM */
 	unsigned		hw_lpm_support:1;
+	/* cached usb2 extened protocol capabilites */
+	u32                     *ext_caps;
+	unsigned int            num_ext_caps;
 	/* Compliance Mode Recovery Data */
 	struct timer_list	comp_mode_recovery_timer;
 	u32			port_status_u0;