i965: Add a new brw_device_info structure.

i965: Add a new brw_device_info structure.

The idea is that struct brw_device_info should store statically-known
information about hardware features.  Using the new family name in the
PCI ID table, we can easily grab the right structure.

This is basically the equivalent of intel_device_info in the kernel.

This patch also makes the new structure available from intel_screen, but
nothing uses it.  Right now, it looks very redundant with existing
fields, but that will change.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>