usb: pd: Start USB host mode functionality with SRC_STARTUP

USB super speed host mode functionality and DP can be supported
concurrently. Hence start USB host functionality into super speed
mode on entering to SRC_STARTUP state. This change removes delayed
USB host mode functionality based on status of non-PD capable device
OR PD non-DP capable device.

Change-Id: Iffebe0077222872039d5547ea8cdbef057a75ca5
Signed-off-by: Mayank Rana <mrana@codeaurora.org>