dwc3: Use otg_sm_work state machine for host and device only mode

This change starts using OTG state machine for host only mode or
device only mode functionality.
There are couple of motivations for this:
1. To make sure host only mode related usb hardware initialization
sequence remains same as OTG mode based host mode functionality
2. To avoid having two different path to support same host mode
functionality or device only mode functionality

Change-Id: I64ab823f6a9b4c1a4918f0eb63bfb03359010c1c
Signed-off-by: Mayank Rana <mrana@codeaurora.org>