mesa: enable crocus driver for older intel graphics

mesa: enable crocus driver for older intel graphics

See here for the full story:
https://www.phoronix.com/scan.php?page=news_item&px=Intel-Crocus-Default-Gallium3D

Once crocus does become the default over i965, upstream is likely to retire
classic pre-gallium drivers altogether, which (with the exception of
i965, superseded by crocus) are all for retrocomputing hardware.

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>