msm: cpr-regulator: add support for high turbo ceiling voltage

Current design to use fixed ceiling voltage for the chip is not
flexible when the chip could support higher speed/voltage bin.
Add a property to pass initial turbo voltages so that
the driver could see and support higher ceiling voltage.

Change-Id: I3d87b5ea28cf3008a7df23c690fa90b17d6ea1d0
Signed-off-by: Ke Liu <keliu@codeaurora.org>