Re-enable vxcan (CONFIG_CAN_VXCAN) for automotive

JIRA: https://issues.redhat.com/browse/RHEL-83276
Upstream-status: RHEL-only

The vxcan module is a software-only CAN bus driver that implements CAN
bus interface pairs. It is similar to veth but for CAN bus. The main
application is to test the various CAN bus protocol layers without
requiring real CAN bus hardware.

Signed-off-by: Radu Rendec <rrendec@redhat.com>

Author: rrendec