i965: Query and store GPU properties from kernel

i965: Query and store GPU properties from kernel

Certain products are not uniquely identifiable based on device id alone. The
kernel exports an interface to help deal with this. This patch merely introduces
the consumer of the interface and makes sure nothing breaks.

It is also possible to use these values for programming GPGPU mode, and I plan
to do that as well.

The interface was introduced in libdrm 2.4.60, which is already required, so it
should all be fine.

v2: Some minor changes recommended by Matt

Signed-off-by: Ben Widawsky <benjamin.widawsky@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>