power: smb5-lib: apply ILIM offset only if CP is enabled

In case of QC 3.0 with SMB1390 configuration, SMB1390 input
current is restricted to 90% of the configured ILIM, to compensate
for this restriction an offset current is applied on top of main
charger's FCC configuration, add check to apply this offset only
when SMB1390 is charging. Rerun fcc_votable whenever CP ILIM is
configured to ensure main charger's FCC offset is recalculated
based on current ILIM.

Change-Id: Ibb10c6489014fcaecd767341a5c63999ab95dd1d
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>