sysvinit-inittab: Fix no tty in runlevel 1.

When switch to runlevel 1 (Single user mode), tty was not
re-spawn and appears to be a machine hang.

[YOCTO #5336]

Signed-off-by: Aníbal Limón <anibal.limon@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>