power: smb5-lib: Fix CONT_AICL_THRESHOLD configuration

During EOC or hard JEITA condition, charging is stopped on the main
charger. In CC mode charging, when VBUS is requested at 5 V with USBIN
allowance still in CONTINUOUS mode, CONT_AICL_THRESHOLD is set to 5 V
(which is incorrect). This causes the main charger never resume charging
from that state (e.g. when hard JEITA condition goes away) as USBIN
stays collapsed due to the 5V AICL threshold. To fix this, set
CONT_AICL_THRESHOLD to 4V for this case.

Change-Id: Id7a5516bedc695e8e47912dd40e141ad17cece42
Signed-off-by: Fenglin Wu <fenglinw@codeaurora.org>