lwis: dpm: allow more control over peak bw vote

Peak BW needs to take the max of read and write bandwidth
into account for a more accurate vote to INT clock. Expose
the necessary fields for this while keep backward
compatibility.

Test: GCA
Bug: 179074308
Bug: 174337332

Signed-off-by: Hossein Mohtasham <hmohtasham@google.com>
Change-Id: I4beb73b479290dbbe8d88b1f80ac91d3baf1d5e0