msm: npu: Add support to notify fw current power level

This change is to add an IPC command to notify fw current power
level during network is running. And since DSP will be notified
when NPU powers on and off by fw during handling this IPC command,
driver doesn't need to notify DSP now.

Change-Id: If3a9157c00990b221d27820f739d589f74a9efc2
Signed-off-by: Jilai Wang <jilaiw@codeaurora.org>