ARM: dts: msm: Add suspend_event_enabled property

To support USB bus suspend functionality, enable USB bus
suspend event using this property.

Change-Id: I0d28536987d48538e375c32f82f836e9b78ea302
Signed-off-by: Guang Jian Zeng <gzeng@codeaurora.org>
Signed-off-by: Bar Weiner <bweiner@codeaurora.org>