Turn consolectl into a simple device node, not a TTY.

Turn consolectl into a simple device node, not a TTY.

Apart from the 16 virtual terminals, Syscons allocates two device nodes
that should not really be TTYs, even though they are. One of them is
consolectl. In RELENG_7 and before, these device nodes are used in
single user mode. After I simplified input path, we only use this device
node to call ioctl() on (moused, Xorg, vidcontrol).

When you call ioctl() on consolectl, it will behave the same as being
called on the first window.