power: smb-lib: start CC2 removal WA when VBUS is low

Currently the CC2 removal workaround starts whenever PD issues a hard
reset. When PD issues a hard reset it is not guaranteed that VBUS will
fall since the source may not even be PD capable.

The CC2 removal workaround should only run during the time that VBUS is
low and CC is debounced.

Fix this by scheduling the CC2 removal workaround when VBUS falls and CC
is debounced, and cancel the workaround when either VBUS rises, or the
removal detection is successful.

CRs-Fixed: 2020132
Change-Id: I6475d37911d90805ed8b3bb4b3a26a9f7557ebd6
Signed-off-by: Nicholas Troast <ntroast@codeaurora.org>
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>