x11-drivers/xf86-video-intel: update to 2.99.917.912 (2020-11-16 snapshot)

Changes: https://gitlab.freedesktop.org/xorg/driver/xf86-video-intel/-/compare/5ca3ac1a90af...ad5540f6ecae
PR: 251306
Tested by: Oleksandr Kryvulia, Oleh Hushchenkov
Approved by: zeising