i965: Move device info initialization to common code

i965: Move device info initialization to common code

With perf queries, initializing the device info is much more complex
than just getting a PCI ID and calling gen_get_device_info.  This commit
adds a new gen_get_device_info_from_fd helper in common code which does
all of the requisite kernel queries to get device info including all of
the topology information.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>