[Intel-gfx] VLV updates

[Jesse Barnes]

Lots of updates and additions for VLV, all tested this time.  The
biggest changes are the DPIO programming bits.  Lots of the clock and
lane configuration stuff is off on the other side of DPIO, and these
patches are enough to get dual-head configs working with eDP and HDMI,
complete with hotplug and DPMS support.

Sprites are added as well, as is some initial RPS support.  Other than
that, it's just some small bug fixes and changes to better handle the hw
in different code paths.

Thanks,
Jesse