kern: move SecureAppletMemory/KPageBuffer heap into the ResourceRegion

libraries/libmesosphere/include/mesosphere/init/kern_init_slab_setup.hpp

@@ -42,7 +42,6 @@ namespace ams::kern::init {
     const KSlabResourceCounts &GetSlabResourceCounts();
 
     size_t CalculateTotalSlabHeapSize();
-    NOINLINE void InitializeKPageBufferSlabHeap();
     NOINLINE void InitializeSlabHeaps();
 
 }