power: smb1398-charger: Toggle UVLO for Slave CP on USB removal

In addition to the master CP, toggle the UVLO config for slave CP
on USB removal to avoid poweroff-leakage.

Change-Id: I1f5d5185d003cfe104b4a67efc1fe88f105f0151
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>