loader: Remove address mapping remnants from citra

These mappings are leftovers from citra and don't apply to the Switch.

src/core/loader/loader.h

@@ -5,7 +5,6 @@
 #pragma once
 
 #include <algorithm>
-#include <initializer_list>
 #include <memory>
 #include <string>
 #include <utility>
@@ -207,12 +206,6 @@ protected:
     bool is_loaded = false;
 };
 
-/**
- * Common address mappings found in most games, used for binary formats that don't have this
- * information.
- */
-extern const std::initializer_list<Kernel::AddressMapping> default_address_mappings;
-
 /**
  * Identifies a bootable file and return a suitable loader
  * @param file The bootable file