kern: fix initial process binary load on 2.0.0-4.1.0 (closes #1460)

libraries/libmesosphere/include/mesosphere/kern_initial_process.hpp

@@ -37,4 +37,6 @@ namespace ams::kern {
     KVirtualAddress GetInitialProcessBinaryAddress();
     size_t GetInitialProcessesSecureMemorySize();
 
+    void LoadInitialProcessBinaryHeaderDeprecated(KPhysicalAddress pool_end);
+
 }