power: pmic-voter: use force_val in rerun election

If force_val is used it can be overwritten by rerun election. Fix this
by getting the effective result which takes the force_val into
consideration.

Change-Id: I2d52d0b2cad1d515efaa103187e7197fe78cc106
Signed-off-by: Nicholas Troast <ntroast@codeaurora.org>