msm: npu: Use worker thread to update thermal state

Thermal framework will update thermal state in its interrupt
thread, so the update in npu driver needs to be moved to worker
thread.

Change-Id: Ib06eb336f0caee21374c6c3b33976163dcc3d045
Signed-off-by: Jilai Wang <jilaiw@codeaurora.org>