usb: dwc3-msm: Add support for snps SSPHY suspend in system suspend

Currently the platforms using SNPS SSPHY do not suspend it so as
to receive SS wakeup events via pwr_event_irq. But certain
telematics platforms do not need SS wakeup in system suspend
scenario.
USB wakeup from PM suspend/hibernation is not a requirement for
automotive/telematics platforms. Use enable_wakeup parameter in
dwc3_msm_suspend call to allow SSPHY suspend to happen and also
to keep the IRQs enabled/disabled.

Change-Id: I691585e15539490e63a345fe2b3aacf182352399
Signed-off-by: Ajay Agarwal <ajaya@codeaurora.org>
Signed-off-by: Harsh Agarwal <harshq@codeaurora.org>