msm: kgsl: Add speed bin read capabilities for A306a GPU

A306a GPU have the two different frequency plans. The frequency
plan needs to be loaded dynamically based on the speed bin
information. Add support for A306a gpu to read the speed bin
information and choose frequency plan dynamically.

Change-Id: Iba53d4381d61f23ce1195a147493b0d292cd3723
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>