dwc3-msm: Check usb role switch status

If extcon handler is present and dpdm regulator is absent, current
code starts USB state machine without checking usb role switch status.
This results into USB PHY being reset while ADSP firmware is performing
charger detection. This may result into wrong/invalid charger detection
instead of SDP causing no USB enumeration. Fix this issue by checking
usb role switch status before kicking USB state machine.

Change-Id: Ic25083a74ac867eeb3869588c3060e6bf05e4007
Signed-off-by: Mayank Rana <mrana@codeaurora.org>