msm: pil-gss: Move to common proxy voting

Remove the boiler plate workqueue and proxy voting code and move
to the common proxy infrastructure that the core pil code
provides. This has the added benefit of fixing any issues where
suspend happens before the proxy vote is removed.

Change-Id: Idb7a73f21c1112d42e760d7249557b08755ddcbf
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>