Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r258262:

drm: Support DRM_CAP_TIMESTAMP_MONOTONIC capability

This fixes DPMS with KDE and radeonkms. Without this, the display would
freeze when the monitor is put into sleep state, and only resumes after
several dozens of minutes once the monitor is powered on again.

Tested by: Mathias Picker <Mathias.Picker@virtual-earth.de>

MFC r254840:

drm: Use DRM_IF_MAJOR & DRM_IF_MINOR from drm_core.h

MFC r235783:
Add the code for new Intel GPU driver, which supports GEM, KMS and
works with new generations of GPUs (IronLake, SandyBridge and
supposedly IvyBridge).

The driver is not connected to the build yet.

Add the code for new Intel GPU driver, which supports GEM, KMS and
works with new generations of GPUs (IronLake, SandyBridge and
supposedly IvyBridge).

The driver is not connected to the build yet.

Sponsored by: The FreeBSD Foundation
MFC after: 1 week