usb: usb_bam: usb bam gets device directly from dwc3-msm

Currently USB PHYs are used to get pointer to
usb device for power management operations.
With this change, dwc3-msm driver will update usb_bam
with device pointer on probe.

Change-Id: I87beba912a04dcd7e02565ec342cb4f23689d79a
Signed-off-by: Bar Weiner <bweiner@codeaurora.org>