winsys/radeon: restore the old r600g winsys memory characteristics.

Use VRAM for static and immutable buffers. This restores the
recently removed r600g winsys behaviour for memory locations.
This also improoves rendering times on the gpu for some
OpenSceneGraph based test cases by about 15%.

Signed-off-by: Marek Olšák <maraeo@gmail.com>

src/gallium/winsys/radeon/drm/radeon_drm_bo.c

@@ -530,6 +530,11 @@ radeon_winsys_bo_create(struct radeon_winsys *rws,
             desc.initial_domains = RADEON_GEM_DOMAIN_GTT;
             desc.reloc_domains = RADEON_GEM_DOMAIN_GTT;
             break;
+    case PIPE_USAGE_IMMUTABLE:
+    case PIPE_USAGE_STATIC:
+            desc.initial_domains = RADEON_GEM_DOMAIN_VRAM;
+            desc.reloc_domains = RADEON_GEM_DOMAIN_VRAM;
+            break;
     default:
             if (bind & (PIPE_BIND_VERTEX_BUFFER | PIPE_BIND_INDEX_BUFFER |
                         PIPE_BIND_CONSTANT_BUFFER)) {