soc: qcom: pil: Add functionality to send subsystem status to AOP

With new AOP architecture, AOP does not have any knowledge of which
subsystems are online at a given moment. This can lead to issues when
not all the subsystems are loaded as AOP assumes that they are all on
by default and will block system suspend.

AOP should assume most subsystems are not loaded by default and instead
rely upon the PIL driver to indicate when a subsystem is loaded/unloaded.

Change-Id: I7e36c2e4e0404d64df3bd241b1599cf690fe4506
Signed-off-by: Kyle Yan <kyan@codeaurora.org>