power: qpnp-linear-charger: Cancel vdd_trim alarm on USB removal

There is a possibility that a scheduled vdd_trim alarm work
may fire after USB removal. Fix this by cancelling the alarm
when USB is removed.

CRs-Fixed: 847664
Change-Id: Ia9dd27c6b0715ce78d6467c6ffe877f2ef0e9355
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org&gt;dd>