[memmap] Define an API for managing the system memory map

Define a generic system memory map API, based on the abstraction
created for parsing the FDT memory map and adding a concept of hidden
in-use memory regions as required to support patching the BIOS INT 15
memory map.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/include/bits/memmap.h

@@ -0,0 +1,15 @@
+#ifndef _BITS_MEMMAP_H
+#define _BITS_MEMMAP_H
+
+/** @file
+ *
+ * Dummy architecture-specific system memory map
+ *
+ * This file is included only if the architecture does not provide its
+ * own version of this file.
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#endif /* _BITS_MEMMAP_H */