power: smb1398-charger: Fix wrong IIN value in register

There is possiblity of setting wrong IIN value, if user vote
for greater then IIN_MAX (5000mA <), so fix this by updating
the IIN_MAX as IIN value.

Change-Id: I50df73d71514967d0d383d612f1c9ddba58437ce
Signed-off-by: Rakesh Kota <quic_kotarake@quicinc.com>