dt-bindings: interrupt-controller: renesas,irqc: Add r8a779g0 support

Document support for the Interrupt Controller for External Devices
(INT-EX) in the Renesas R-Car V4M (R8A779H0) SoC.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/264cffccfbb1f92657420f5f869236b06a97d958.1713280616.git.geert+renesas@glider.be


Signed-off-by: Rob Herring (Arm) <robh@kernel.org>