configure: ipaplatform falls back to ID_LIKE
    
    The auto-detection code for IPAPLATFORM now falls back to ID_LIKE.
    
    CentOS platform will now be treated as rhel-like, Ubuntu platforms as
    debian-like automatically.
    
    Fixes: https://pagure.io/freeipa/issue/8689
    Signed-off-by: Christian Heimes <cheimes@redhat.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>