arm64: dts: renesas: hihope-common: Move du clk properties out of common dtsi

RZ/G2N board is pin compatible with RZ/G2M board. However on the SoC
side RZ/G2N uses DU3 where as RZ/G2M uses DU2 for the DPAD. In order to
reuse the common dtsi for both the boards, it is required to move du clock
properties from common dtsi to board specific dts.

Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/1570029619-43238-2-git-send-email-biju.das@bp.renesas.com


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>