Add option of 13 for FORCE_MAX_ZONEORDER

This is a hack, but it's what the other distros currently use
for aarch64 with 4K pages so we'll do the same while upstream
decides what the best outcome is (which isn't this).

Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Signed-off-by: Robert Richter <rrichter@cavium.com>