systemd-logind: Fix vt-enter not working when using a legacy video driver

systemd-logind: Fix vt-enter not working when using a legacy video driver

If there is only a single non kms video device (tested with the vesa driver),
then we will never get a resume signal for a drm node, so also call vtenter
when we get a resume for an input device.

Notes:
1) vtenter checks if it is ok to do the vtenter, so if there are kms video
devices the calls for input device resumes are a nop
2) This assumes that there will always be at least one server event fd
supporting input device. Since all non legacy input-drivers will be patched
to supported server fds this seems a safe assumption.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>