Add armhfp for the existing aarch64 image builds
    
    As part of the UEFI on ARMv7 feature we build the images the same
    as aarch64 using image factory. This is initiall enabling the
    Minimal/Server/Workstation images to allow wider testing. Once we
    know they're good we'll move all the others over and remove the old
    build mechanism that uses appliance-creator.
    
    Signed-off-by: Peter Robinson <pbrobinson@fedoraproject.org>