arm64: dts: renesas: use extended audio dmac register

Basic audio dmac register only supports busif from 0 to 3,
in order to use busif4 ~ busif7, extended audio dmac register
need to be used.

This patch updates H3 (= r8a7795), M3-W (= r8a7796) and
M3-N (=r8a77965) to use extended audio dmac register set.

Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>