msm: kgsl: Set BIMC vote limits by reading the bus table

Currently a fixed number of BIMC votes are required per GPU
frequency.  Read the enumerated votes directly from the bus
table and set min/max limits on the votes dynamically.

Change-Id: I7d8118f658e6a8225291b8353301413252f1f3f7
Signed-off-by: Lucille Sylvester <lsylvest@codeaurora.org>