ARM: dts: msm: update regulator configurations for 8996AU CDP

As per the hardware documentation, update the voltage regulator
configurations needed for 8996AU CDP. This overrides the settings
done in msm8996-regulator.dtsi.

CRs-Fixed: 978343
Change-Id: I250e5c6e7f6d80ab1415b873c9ed6e405aae0c4c
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>