xserver-xorg: import distro patch to use modesetting driver on newer hardware

xserver-xorg: import distro patch to use modesetting driver on newer hardware

Debian and Fedora both carry this patch, and the xf86-video-modesetting
driver seems better on recent hardware.

As an example, on a NUC6CAYS, the x11perf -aa10text and -rgb10text tests
see around a 20x increase.

[YOCTO #12019]
[YOCTO #12390]

Signed-off-by: California Sullivan <california.l.sullivan@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>