arm64: dts: renesas: Add LCDC overlays for RZ/T2H and RZ/N2H EVKs

Add DT overlay support for enabling the DU/LCDC pipeline on the RZ/T2H
and RZ/N2H evaluation kits when fitted with an ADV7513 HDMI transmitter
on CN15/CN20.

Share the common ADV7513 and LCDC pin configuration between the two
overlays. Disable board functions whose pins are reassigned to LCDC,
including the affected LEDs, SDHI0 on the RZ/T2H EVK, and I2C0 on the
RZ/N2H EVK.

Move the LED8 and LED9 preprocessor conditionals inside the node
definitions so that the nodes remain present in the base DTS. This
allows the LCDC overlays to reference and disable the LEDs when their
pins are reassigned to display functions.

Configure the LCDC data and clock pins with slew-rate setting 1 as
recommended by the hardware manual. Use slew-rate setting 0 for the
HSYNC, VSYNC and DE pins, as testing with the ADV7513 showed unstable
display output and visible flicker when these synchronization signals
were configured for fast slew rate.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260819183829.3953529-3-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

0 files changed, 0 insertions, 0 deletions