gallium: add support for aliased 4ub format

src/mesa/pipe/draw/draw_vertex_fetch.c

@@ -80,6 +80,8 @@ fetch_attrib4(const void *ptr, enum pipe_format format, float attrib[4])
       break;
 
    case PIPE_FORMAT_A8R8G8B8_UNORM:
+   case PIPE_FORMAT_U_A8_R8_G8_B8:
+   case PIPE_FORMAT_R8G8B8A8_UNORM:
       attrib[0] = (float) ((unsigned char *) ptr)[2] / 255.0f;
       attrib[1] = (float) ((unsigned char *) ptr)[1] / 255.0f;
       attrib[2] = (float) ((unsigned char *) ptr)[0] / 255.0f;