USB: dwc3-msm: Don't schedule sm_work initially during probe

Currently driver schedules sm_work with no delay in probe and due to this,
sm_work doesn't wait for initial VBUS state notification and goes ahead
with USB block reset and USB initialization as VBUS is not set. This will
interfere with PMIC's charger detection.  Hence don't schedule sm_work in
probe as PMIC always notifies initial VBUS state. Also don't flush sm_work
for initial notification from PMIC during bootup. Otherwise VBUS state
doesn't get updated before sm_work starts executing.

Also set typec_current_max to zero during disconnect.

Change-Id: I89cde170debb43ca3198076fb47c7eef6789846d
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>