usb-tablet: Don't claim wakeup capability for USB-2 version

Our ehci code does not implement wakeup support, so claiming support for
it with usb-tablet in USB-2 mode causes all tablet events to get lost.

http://bugzilla.redhat.com/show_bug.cgi?id=929068

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
(cherry picked from commit aa1c9e9)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

hw/usb/dev-hid.c

@@ -236,7 +236,7 @@ static const USBDescDevice desc_device_tablet2 = {
             .bNumInterfaces        = 1,
             .bConfigurationValue   = 1,
             .iConfiguration        = STR_CONFIG_TABLET,
-            .bmAttributes          = 0xa0,
+            .bmAttributes          = 0x80,
             .bMaxPower             = 50,
             .nif = 1,
             .ifs = &desc_iface_tablet2,