regulator: cpr3-mmss-regulator: add support for msm8996pro speed bins

MSM8996-Pro chips contain a fuse which defines the GPU speed bin.
Each speed bin supports a different GPU maximum frequency.  Add
support to read this speed bin fuse and use it to parse device
tree properties appropriately.

Change-Id: Ib9b0ba170287ae30802bdb0c64faead8c9bdee8c
Signed-off-by: David Collins <collinsd@codeaurora.org>