yocto,components/safety_island: Use VLAN for Kronos network

Use Openvswitch and VLANs setup for the Kronos network.

Change zephyr HIPC overlays to include the Kconfig parameter
that enables the VLAN network handling.

Rework the systemd network configuration files to unify baremetal
and virtualization profiles.

Introduce a new systemd service that brings up the Openvswitch
bridges at startup, Openvswitch remembers the configuration across
the reboots, so this service will run every startup but will create
the bridges only the first time.

Introduce a systemd drop-in file for the xendomains service
that introduces a dependency between the above newly introduced
service and the xendomains one, only under virtualization profile.

Modify the domu-package variables to use the Xen scripts for
openvswitch that adds the guests port into the bridges, while
there, add a newline to the DOMU{1,2}_EXTRA variable to let it land
on the created configuration file as end of file blank line.

Modify fvp_rd_kronos_safety_island_c0_actuation.conf board to
include a Kconfig parameter for the VLAN id of the second interface
and while there, disable the net "config" library module since the
application is already setting the network configuration by itself.

Add entries to the dictionary.

Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>