power: battery: Allow taper exit if increase in float voltage

Due to reduction of float voltage in JEITA condition, taper charging can
be initiated at a lower float voltage value. On removal of JEITA
condition, float voltage scales back to its default value, but as per
current SW design, once taper charging is initiated, the taper-check loop
does not exit until parallel is disabled. Due to this, FCC does not scales
back to its default value, and parallel too stays disabled leading to slow
charging thereafter with lower FCC.

Add support to exit taper charging on increase in float voltage if it
was initiated on reduced float voltage, due to jeita.

Change-Id: I5bc127253f5a303c5b0b05683ce68f0bacd79eda
Signed-off-by: Umang Agrawal <uagrawal@codeaurora.org>