4.6 DRM/i915 update CFT (Sandy Bridge?)/IvyBridge/Haswell/Broadwell/SkyLake/KabyLake supported

[Juan Ramón Molina Menor]

Hi!

Your commits overnight have restored and even improved the performance 
with my Haswell (HD 4400) GPU: Lower CPU usage and snappier resize / 
full-screen changes.

But on the other hand, loading the i915kms module through startx 
(non-root) panics, I have to use kldload i915kms.

Also, changing the power mode (plugging or unplugging the power cord) 
leads to instant panic, while with the drm-next-3.9 branch, switching 
AC/battery modifies backlight value up and down without issues. I have 
replaced the screenshot:

https://wiki.freebsd.org/Laptops/ThinkPad_S440?action=AttachFile&do=get&target=panic-DRM-46.jpg

Best regards,
Juan