Add the .img files into grub2-pc-modules (and all legacy variants)
    
    autoqa is seeing a failure that looks like:
    
    13:50:17,909 INF program: grub2-install: error: cannot open `/usr/lib/grub/i386-pc/lzma_decompress.img': No such file or directory.
    
    And it's because the .img files are currently excluded.  So put them
    back.
    
    Signed-off-by: Peter Jones <pjones@redhat.com>