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 r254819:

drm: Don't delete already deleted iicbus child from drm_iic_dp_aux

The iic_dp_aux_detach callback is therefore useless: it's replaced by
bus_generic_detach. This fixes a "General protection fault" panic during
second (incorrect) deletion of the child.

Tested by: kwm@
Reviewed by: ray@

MFC r249041, r249249:

drm and i915: Left-shift iic_msg.slave at creation time

This is required because, in the radeon driver, we can't left-shift in a
central place, like it was done in the i915 driver.

Reviewed by: kib@, kan@, avg@
Tested by: kib@, avg@,
Olivier Cochard-Labbé <olivier@cochard.me>

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