git: drm - Update to Linux 4.20.17

[Sergey Zigachev]

> I ran glxinfo to test hardware acceleration but it is not working.

Which Xorg driver are you using? If you use modesetting, then you have 
to rebuild Xorg package with patch I posted earlier and then enable 
acceleration with this parameter in config:

Option "AccelMethod" "glamor"

You can also test with intel Xorg driver, just make sure you're using 
SNA acceleration.

If all of that doesn't work, please post dmesg output, there can be 
other issues. I tested only on Intel Core i5 8250U processor.

-Sergey