drm/i915: Update ivybridge_init_clock_gating()

* Synchronize it with Linux 3.8.13

* This commit fixes a flickering issue with some laptop screens

Reported-by: luxh
drm: Add linux/io.h
drm/i915: Sync drm_irq.c with Linux 3.8.13

Most significant change: an interrupt handler called when parity errors
are detected in the GPU L3 cache of Ivy Bridge+ CPUs.
kernel: Add the mrsas(4) RAID driver for LSI Thunderbolt and newer series.

Specifically, it adds support for Thunderbolt (6 Gb/s), Invader (12 Gb/s)
and Fury (12 Gb/s) series.

Note that Thunderbolt controllers are supported by mfi(4) too. When both
drivers are loaded, the default is to attach via mfi(4). This can be
changed by either not loading or compiling in the mfi(4) driver at all
or by setting hw.mfi.mrsas_enable=1 in /boot/loader.conf. It might be
that we change this default to giving precedence to mrsas(4) before the
next release, but for now, until it gets some more testing, we take
FreeBSD's default (giving mfi(4) precedence).

That said, the driver works without any issues here with an
Intel RS25DB080 card (which is really an LSI MegaRAID SAS 9265).

mrsas(4) should (at least) support the following adapters:

Thunderbolt:

LSI MegaRAID SAS 9265
LSI MegaRAID SAS 9266
LSI MegaRAID SAS 9267
LSI MegaRAID SAS 9270
LSI MegaRAID SAS 9271
LSI MegaRAID SAS 9272
LSI MegaRAID SAS 9285
LSI MegaRAID SAS 9286
DELL PERC H810
DELL PERC H710/P

Invader/Fury:

LSI MegaRAID SAS 9380
LSI MegaRAID SAS 9361
LSI MegaRAID SAS 9341
DELL PERC H830
DELL PERC H730/P
DELL PERC H330

Taken-from: FreeBSD