[BOOT] Add EFI headers and entry point

BOOT/ENVIRON/INC/nt.h

@@ -0,0 +1,23 @@
+/*++
+
+Copyright (c) 2024, the LibreXP developers.
+Provided under the BSD 3-Clause license.
+
+Module Name:
+
+   nt.h
+
+Abstract:
+
+   Provides NT header files.
+
+--*/
+
+#ifndef _NT_H
+#define _NT_H
+
+#include <ntdef.h>
+#include <ntstatus.h>
+#include <ntimage.h>
+
+#endif