intel_chipset: Merge intel-gpu-tools chipsets

Intel GPU Tools is newer and arguably better. This change doesn't
completely merge the files because it's a bit simpler if we move the
I9XX macro over to Intel GPU Tools, and don't move over a few macros
from IGT that libdrm doesn't care about.

It has been discussed, and would seem even easier if Intel GPU Tools
simply used the libdrm header files. Whether or not we move to that,
this should help that effort.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>