dt-bindings: mmc: mtk-sd: Add support for MT8196

Extend the devicetree bindings to include the MT8196 mmc controller,
new tx/rx would be supported from MT8196, and the register settings
of STOP_DLY_SEL and POP_EN_CNT would also be variant.

Signed-off-by: Andy-ld Lu <andy-ld.lu@mediatek.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Message-ID: <20241011024906.8173-4-andy-ld.lu@mediatek.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>