usbcore: check device's LPM capability

Check device's LPM capability by examining the bmAttibutes field of the
USB2.0 Extension Descriptor.

Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 90ab9dc..1d00d9bc 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -410,6 +410,7 @@
  *	FIXME -- complete doc
  * @authenticated: Crypto authentication passed
  * @wusb: device is Wireless USB
+ * @lpm_capable: device supports LPM
  * @string_langid: language ID for strings
  * @product: iProduct string, if present (static)
  * @manufacturer: iManufacturer string, if present (static)
@@ -472,6 +473,7 @@
 	unsigned authorized:1;
 	unsigned authenticated:1;
 	unsigned wusb:1;
+	unsigned lpm_capable:1;
 	int string_langid;
 
 	/* static strings from the device */