power: qpnp-bms: fix divide by 0 issue when charging

The current code can divide by zero in the scale_soc_while_chg
function if calculated_soc drops while charging.

Fix the issue by not scaling soc if catch_up_time_us is zero.

Change-Id: I9cc2867b0c961a9b5c7031767b956bbfecfeebe6
Signed-off-by: Xiaozhe Shi <xiaozhes@codeaurora.org>