arm64: dts: renesas: hihope-rzg2-ex: Enable CAN interfaces

This patch enables both CAN0 and CAN1, both exposed via
connectors found on the expansion board.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>