arm64: dts: renesas: rzt2h-n2h-evk-common: Use GPIO for SD0 write protect

arm64: dts: renesas: rzt2h-n2h-evk-common: Use GPIO for SD0 write protect

Switch SD0 write-protect detection to a GPIO on the RZ/T2H and RZ/N2H
EVKs. Both boards use a full-size SD card slot on the SD0 channel with
a dedicated WP pin.

The RZ/T2H and RZ/N2H SoCs use of_data_rcar_gen3, which sets
MMC_CAP2_NO_WRITE_PROTECT and causes the core to ignore the WP signal
unless a wp-gpios property is provided. Describe the WP pin as a GPIO
to allow the MMC core to evaluate the write-protect status correctly.

Fixes: d065453e5ee0 ("arm64: dts: renesas: rzt2h-rzn2h-evk: Enable SD card slot")
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/20260106131319.643084-1-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>