BugLink: http://bugs.launchpad.net/bugs/1566221

This option allows userspace to pass the RSDP address to the kernel, which
makes it possible for a user to circumvent any restrictions imposed on
loading modules. Disable it in that case.
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>