regulator: qpnp-labibb-regulator: fix the delay setting for LAB/IBB

Currently while setting the voltage for LAB/IBB regulators delay is
configured wrongly because of setting an additional bit. Fix it.

CRs-Fixed: 782661
Change-Id: I56341c9c1c8f82be25593926f807446017e30eac
Signed-off-by: Ke Liu <keliu@codeaurora.org>