The `enable_console_login` function modifies `/etc/inittab` to enable
logins on a serial device. For virtio serial devices, a getty is
configured to launch on `hvc0`; for other devices, it is configured for
`ttyS0` (the default).
When using the `configure.configure` function to automatically configure
a virtual machine, `enable_console_login` is called if a console device
is specified in the VM definition.