arm64: dts: renesas: hihope-rzg2-ex: Separate out lvds specific nodes into common file

Separate out LVDS specific nodes into common file
hihope-rzg2-ex-lvds.dtsi so that this can be re-used by RZ/G2M[N]
variants.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Marian-Cristian Rotariu <marian-cristian.rotariu.rb@bp.renesas.com>
Link: https://lore.kernel.org/r/1593004330-5039-8-git-send-email-prabhakar.mahadev-lad.rj@bp.renesas.com


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