hap is enabled by default in xm and xl config and usually only
specified when it is desirable to disable hap (hap = 0). Change
the xm,xl <-> xml converter to behave similarly. I.e. only
produce 'hap = 0' when <hap state='off'/> and vice versa.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>