ARM: dts: msm: Add support to vote for 3.15 V on LDO 24 for msm8994

USB2 snps picoPHY does not operate correctly during full speed host
mode at subzero temperature. Work around this issue by increasing
the maximum allowed PM8994 LDO 24 voltage from 3.05 V to 3.15 V.

Change-Id: I0a47c82fd63875eeb37076604bda356fd051f970
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>