ETZPC is a firewall controller. Put all peripherals filtered by the
ETZPC as ETZPC subnodes and keep the "simple-bus" compatible for
backward compatibility.
Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>