Move grubby and grubby-deprecated from @core to @arm-tools
    
    Adding them into @core was supposed to make them show up in some
    install trees, according to the commit message, but it broke
    regular BLS installs:
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1654036
    
    which is obviously a major problem. I *think* moving the entries
    to arm-tools should ensure the packages are in the relevant trees
    without breaking BLS installs.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>