msm: npu: Add auto PIL support

This change is to add auto PIL support for NPU. It will create a
sysfs node which can be used to preload NPU fw during system boots
up. When executing networks, driver won't load fw, but only turn on
NPU power and clocks.

Change-Id: I7ab37ae73db8ff6e1a2f88c5707ff861cf0268b3
Signed-off-by: Jilai Wang <jilaiw@codeaurora.org>