This adds a new livemedia-creator argument, --extra-boot-args, which can
be used to add arguments to the kernel command-line in the templates.
Related: rhbz#1687743
This enables Baytrail and similar atom CPUs that typically ship with a
32-bit firmware, but have a 64-bit capable CPU.
Signed-off-by: Peter Jones <pjones@redhat.com>
