include/ttyutils: add default chardata

this one moves the init_chardata to include/ttyutils.h as well as to
lib/include/ttyutils.c.  Also the macros CTL/CTRL are fixed in
agetty.c and sulogin.c to use the XOR variant CTL.

[kzak@redhat.com: use macro rather than global variable for default
                  chardata]

Signed-off-by: Werner Fink <werner@suse.de>
Signed-off-by: Karel Zak <kzak@redhat.com>