usb: dwc3: Add changes to support dual-role switching

usb: dwc3: Add changes to support dual-role switching

This patch is a squash of several commits from msm-3.18 that
add support for dual-role switching (formerly known as "OTG")
to the DWC3 and XHCI platform drivers.

Based on the following commits:

usb: dwc3: Introduce OTG driver for dwc3
usb: dwc3-msm: Add support for LPM on cable disconnect
DWC3: Enable XHCI host in OTG mode
USB: dwc3: Add support for host bus suspend
usb: dwc3 / xhci_plat: Call xhci_suspend/resume when entering/exiting LPM
USB: dwc3: gadget: Implement gadget_vbus_draw() API
USB: gadget: dwc3: Fix composition switch issue during cable disconnect
usb: dwc3: notify gadget disconnect upon VBUS low
usb: dwc3: msm: Remove last of dwc3_otg
dwc3: Reset USB controller/PHY after psy connect indication at bootup
dwc3: Use otg_sm_work state machine for host and device only mode

Signed-off-by: Jack Pham <jackp@codeaurora.org>