USB: msm_otg: Fix BUG when updating charger current from 100 to 500

Commit eb0d6bbe "ci13xxx_udc: Draw 100mA of current in unconfigured
state" introduced a BUG where driver fails to update power supply
max current as 500mA. Due to this PMIC doesn't charge using USB.
Fix this bug by handling this case correctly.

Change-Id: I67329632ff52de44cda9736d5b21727a22d68b9c
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>