power: smb1390: Turn off due to high SOC threshold only at start

Currently, Battery SoC exceeding a user-configurable threshold causes
the SMB1390s to turn off in the following conditions via
SOC_LEVEL_VOTER:
- Upon initial bootup, and
- After initial bootup if charging mode is Constant-Voltage (CV).

Remove the second condition. Now, a high SoC threshold will cause the
SMB1390s to turn off only at bootup. This rule applies to both CV and
Constant-Current (CC) charging modes, irrespective of whether the output
topology is VPH or VBATT.

In addition, if the SoC falls below the threshold after bootup, remove
vote from SOC_LEVEL_VOTER. Without this, CPs will never get re-enabled
if they get disabled by SOC_LEVEL_VOTER upon bootup.

Change-Id: If0ce2661f25fd227cbe969fdbed468236806238f
Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>