Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

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@

drm: Right-shift I2C slave address before passing it to aux channel

In r249041, I2C slave addresses were left-shifted at creation time to
have the same behavior between i915 and radeon (not committed yet). This
change broke the aux channel. The user-visible change was that display
port on i915 didn't work anymore.

To fix this, we right-shift the address back to restore the original value.

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

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