tests: Replace texture change colors with initial colors

We used to init texture with default colors and if you wanted something different, we'd map the image, change the colors and unmap the image.  With Nvidia and optimal_tiled textures, this would turn into create a linear image, write new colors to it and issue a copy command to copy it to the real texture image.  Since all the tests knew the colors they wanted at texture construction time, it seemed better/easier to chage the constructor to just take the colors if non-default was desired.
diff --git a/tests/xglrenderframework.h b/tests/xglrenderframework.h
index ac8ed07..7963caa 100644
--- a/tests/xglrenderframework.h
+++ b/tests/xglrenderframework.h
@@ -246,10 +246,10 @@
 class XglTextureObj : public xgl_testing::Image
 {
 public:
-    XglTextureObj(XglDevice *device);
-    void ChangeColors(uint32_t color1, uint32_t color2);
+    XglTextureObj(XglDevice *device, uint32_t *colors = NULL);
     XGL_IMAGE_VIEW_ATTACH_INFO m_textureViewInfo;
 
+
 protected:
     XglDevice                 *m_device;
     xgl_testing::ImageView     m_textureView;