intel: get depth/stencil layout from VkRenderPassCreateInfo

We will not be able to tell RT and DS from VkFramebufferCreateInfo after an
upcoming header change.
diff --git a/icd/intel/fb.h b/icd/intel/fb.h
index fe1cba4..fa9c1c1 100644
--- a/icd/intel/fb.h
+++ b/icd/intel/fb.h
@@ -36,7 +36,6 @@
     uint32_t rt_count;
 
     const struct intel_ds_view *ds;
-    bool optimal_ds;
 
     uint32_t sample_count;
     uint32_t width;
@@ -62,6 +61,7 @@
     uint32_t stencilLoadClearValue;
     VkImageLayout depthStencilLayout;
     VkFormat depthStencilFormat;
+    bool optimal_ds;
 };
 
 static inline struct intel_fb *intel_fb(VkFramebuffer fb)