dts: arm: Add Renesas r8a779f0 support

r8a779f0 is also know as S4, this SoC is part of the Gen4 SoC series,
has 8 Cortex-A55 and a dual core lockstep Cortex-R52 processor.

SCIF0 is dedicated to Zephyr and SCIF3 to Linux.

**Control Domains**
IMPORTANT: This SoC is divided into two "domains":
- Application domain contains some peripherals as well as A55 & R52 cores.
- Control domain that contain a G4MH/RH850 MCU and other peripherals.

In order to access control domain peripherals such as gpio4-7 and CAN-FD
from application domain, the G4MH MCU has to unlock a protection
mechanism from control domain buses.

"Protected" controllers will be flagged in gen4 device trees,
warning users that they need to flash a custom G4MH firmware
to unlock access to these controllers.

**Clock controller**
This SoC clock controller is offering "domains"
for each world (Zephyr/Linux).

These domains are several "entry points" to the clock controller
which are arbitrated to avoid a world from turning off a clock needed
by another one.

We decided to use the same domain as Linux because the
security mechanism as to be implemented before accessing
another domain.

Signed-off-by: Aymeric Aillet <aymeric.aillet@iot.bzh>