remove bitmap

kernel/memory/pageframe.h

@@ -5,10 +5,12 @@
 
 class PageFrame {
     private:
+    public:
         uintptr_t address;
         uintptr_t mapped_address;
-    public:
+        bool available;
         PageFrame* queue_link;
+        PageFrame(){};
         PageFrame(uintptr_t a):address(a){};
         uintptr_t getAddr(){return address;};
         uintptr_t getVirtualAddr(){return address;};