radeonsi: enable multi-draw related pipe caps

This enables GL_shader_draw_parameters and GL_ARB_indirect_parameters as well
as a properly accelerated implementation of GL_ARB_multi_draw_indirect.

Enabling the feature requires a sufficiently uptodate firmware -- those have
already been released a long time ago, although this does mean that the
feature only works with the amdgpu kernel module, since the radeon module
doesn't have a way to query the firmware version.

Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>

docs/relnotes/12.1.0.html

@@ -45,6 +45,8 @@ Note: some of the new features are only available with certain drivers.
 
 <ul>
 <li>GL_ARB_enhanced_layouts on i965</li>
+<li>GL_ARB_indirect_parameters on radeonsi</li>
+<li>GL_ARB_shader_draw_parameters on radeonsi</li>
 <li>GL_ARB_shader_group_vote on nvc0</li>
 <li>GL_ARB_ES3_1_compatibility on i965</li>
 <li>GL_EXT_window_rectangles on nv50, nvc0</li>