r600g: handle PIPE_SHADER_CAP_OUTPUT_READ

Signed-off-by: Vadim Girlin <vadimgirlin@gmail.com>

src/gallium/drivers/r600/r600_pipe.c

@@ -513,6 +513,8 @@ static int r600_get_shader_param(struct pipe_screen* pscreen, unsigned shader, e
 		return 0;
 	case PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS:
 		return 16;
+	case PIPE_SHADER_CAP_OUTPUT_READ:
+		return 1;
 	default:
 		return 0;
 	}