Log Message:
The pkgsrc framework has become more strict, and registering fonts for
installation per FONTS_DIRS.x11 will mandate an X11 dependency.

At this point, only the x-symbol package is concerned. Since it needs
to be able to cope with a non-graphical console anyway, we install it
unconditionally, skip the PLIST dance, and just depend the font
registration on X11 availabiluty.