msm: kgsl: Correct the bandwidth vote translation

The numbers stored in ib_votes will be multipled by
1024 * 1024 to be translated into a bandwidth request.
That is the value they need to be divided by with the
result rounded down before storage.

Change-Id: Ib171d2bbf58911cbf0423d3b1365d3917abe5f19
Signed-off-by: Lucille Sylvester <lsylvest@codeaurora.org>