gallium: add PIPE_QUERY_SO_OVERFLOW_ANY_PREDICATE and corresponding cap

v2: rename cap to PIPE_CAP_QUERY_SO_OVERFLOW and be a bit more explicit
    in the documentation

Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>

src/gallium/drivers/softpipe/sp_screen.c

@@ -307,6 +307,7 @@ softpipe_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_POST_DEPTH_COVERAGE:
    case PIPE_CAP_BINDLESS_TEXTURE:
    case PIPE_CAP_NIR_SAMPLERS_AS_DEREF:
+   case PIPE_CAP_QUERY_SO_OVERFLOW:
       return 0;
    case PIPE_CAP_SHADER_BUFFER_OFFSET_ALIGNMENT:
       return 4;