From anaconda-37.12.1, anaconda defaults to GPT for all BIOS
installs. So we need to create a BIOS boot partition when doing
a BIOS install. I think all other potential configs (x86_64
UEFI, aarch64 (UEFI), ppc64le (OFW)) are covered under the other
two paths, so just making this `else` should be OK.
Signed-off-by: Adam Williamson <awilliam@redhat.com>
