usb: dwc3-msm: Add support to handle floating D+/D- lines

There is a possibility of PMI detecting SDP as a floating charger
when connected to a PC. Workaround this issue by starting peripheral
stack for floating charger as well. After 10 sec check for USB device
enumeration using gadget USB state. If device is indeed connected to
SDP gadget usb state will be USB_STATE_DEFAULT or higher. This change
also helps to start peripheral stack in super speed usb compliance mode
when D+ and D- lines are floating.

Change-Id: Ia6dc668c549dca35e3273ece9a43be52c25d40ad
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>