on arm disk images make sure there is not a console=tty0 bootarg
    
    Appending console=tty0 is problematic for many arm use cases.
    lets make sure we remove it so systems can just boot
    https://bugzilla.redhat.com/show_bug.cgi?id=2022757
    
    Signed-off-by: Dennis Gilmore <dennis@ausil.us>