power: smb5-lib: Fix low USB input current limit issue

There are cases where SDP is gone but its vote for USB ICL remains,
as a result, bringing down the total USB input.

In one case, after USB/SDP removal, USB driver still notifies charger
to suspend USB, which blocks charging on subsequent charger insertion.
Fix it by ignoring the request when USB is not present.

When the device boots with PD adapter attached, and if APSD happens to
detect SDP, there will be a SDP 100mA vote for USB ICL, remaining even
after PD contract is established. Fix it by cancelling the vote when
PD becomes active.

Change-Id: Ie18c24c1d0b27b2beefbebb757d72b85a8725cc1
Signed-off-by: Harry Yang <harryy@codeaurora.org>