ARM: dts: msm: delete voltage raising properties for msm8926-v2

There is no need to change the default minimum and initial voltages for
msm8926-v2 chips. Hence remove the properties responsible for enabling the
uplift and conditional minimum voltage workarounds from the msm8926-v2
device tree.

CRs-Fixed: 607899
Change-Id: Ic5af7cf77299dc6d46000b620660620f34eec5cb
Signed-off-by: Ke Liu <keliu@codeaurora.org>