power: smb1360: Do not disable charging to cutoff USB input current

To disable the input current from USB the software driver disables
charging. If the charging stays disabled at power-off, it remains
disabled forever even at the next power-on. This is because in some
designs the SMB1360 does not get reset across power-offs and continues
with the last configuration when it was powered on.

Fix this by setting the charge current to minimum instead of disabling
charging. This keeps charging enabled in all scenarios. However, the
device will charge with a minimum current of 100mA as long as the
charger is present.

Change-Id: I4630c779ec70ac1dd0c397ffc22fbc2b8ef40cff
Signed-off-by: Fenglin Wu <fenglinw@codeaurora.org>