ARM: dts: r8a77470: Add CMT SoC specific support

Add CMT[01] support to r8a77470 SoC DT.

Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>