dri: Add function to implement queries common to all Mesa drivers

dri: Add function to implement queries common to all Mesa drivers

v2: Add assertions that the version string has the expected format.
This will catch build errors (or changes to the version string format)
in debug build without exposing release builds to buffer over-runs.
Suggested by Ken.

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