lwis: dpm: allow peak bw control from user mode

Allow ISP user driver control the peak bandwidth directly
for more flexibility dealing with workarounds and other
conditional peak adjustments.

Bug: 179074308
Bug: 174337332

Signed-off-by: Hossein Mohtasham <hmohtasham@google.com>
Change-Id: Idd5ab6a560070cf6a70f202272449bd9c7da5493