r600g: move all query code into r600_query.c

r600g: move all query code into r600_query.c

And rename or inline functions where appropriate.
There is no reason to keep this stuff in r600_hw_context.c.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>