battery: fix sw jeita's Float Voltage control

Currently FV is a max voter where it may not end up reducing
it if jeita wants to lower it.

Moreover Qnovo shouldn't be allowed to vote higher than the
FV voted by battery profile.

Change it to a min voter. While at it remove the mutual exclusion
between profile voter and qnovo voter.

Change-Id: Ic3a597a5d3931932950123370a04a45e07d16b68
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>