arm64: dts: renesas: r8a77961-ulcb: add HDMI Display support

This patch enables HDMI Display on M3ULCB with R-Car M3-W+.

Signed-off-by: Yuya Hamamachi <yuya.hamamachi.sx@renesas.com>
Link: https://lore.kernel.org/r/20210217090603.1517-1-yuya.hamamachi.sx@renesas.com


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