gallium: add pipe_screen::get_driver_query_group_info

gallium: add pipe_screen::get_driver_query_group_info

Driver queries are organized as a single hierarchy where queries are
categorized into groups. Each group has a list of queries and a maximum
number of queries that can be sampled. The list of available groups can
be obtained using pipe_screen::get_driver_query_group_info.

This will be used by GL_AMD_performance monitor.

v2: add group type (CPU/GPU)

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Martin Peres <martin.peres@free.fr>