r600g/compute: PIPE_CAP_COMPUTE should be false for pre-evergreen GPUs

This prevents clover from using unsupported devices.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

CC: "10.0 10.1" <mesa-stable@lists.freedesktop.org>
diff --git a/src/gallium/drivers/r600/r600_pipe.c b/src/gallium/drivers/r600/r600_pipe.c
index f2782e6..2fceb3c 100644
--- a/src/gallium/drivers/r600/r600_pipe.c
+++ b/src/gallium/drivers/r600/r600_pipe.c
@@ -348,7 +348,6 @@
 	case PIPE_CAP_VERTEX_ELEMENT_SRC_OFFSET_4BYTE_ALIGNED_ONLY:
 	case PIPE_CAP_USER_INDEX_BUFFERS:
 	case PIPE_CAP_USER_CONSTANT_BUFFERS:
-	case PIPE_CAP_COMPUTE:
 	case PIPE_CAP_START_INSTANCE:
 	case PIPE_CAP_MAX_DUAL_SOURCE_RENDER_TARGETS:
 	case PIPE_CAP_TEXTURE_BUFFER_OBJECTS:
@@ -358,6 +357,9 @@
         case PIPE_CAP_BUFFER_MAP_PERSISTENT_COHERENT:
 		return 1;
 
+	case PIPE_CAP_COMPUTE:
+		return rscreen->b.chip_class > R700;
+
 	case PIPE_CAP_TGSI_TEXCOORD:
 		return 0;