devfreq: Add static table mapping governor for NPU

Static map governor registers for NPU clock notifier and
votes for the DDR clock to match the NPU clock's voltage
corner. The core-dev table maintains the NPU to DDR clock
mapping to match the voltage corners. This governor helps
reduce the power when NPU clock is at lower voltage corners.

Change-Id: I6477b13994ca5ca21362e13083535c4280557d4d
Signed-off-by: Rama Aparna Mallavarapu <aparnam@codeaurora.org>