pca9468_charger: rx_vol adjust stage stop increasing power when hit VFLT_LOOP

stop increasing the input power when iin < iin_cc and status hit VFLT_LOOP
The device entered CV mode, so the iin could not increase
during the adjustment.
Stop increasing voltage to prevent requesting
too much power and causing thermal concern.

Bug: 199239859
Signed-off-by: Wasb Liu <wasbliu@google.com>
Change-Id: Ic5729bb5b643fcb6f254f7b4d74de337f1530b9d