spi: mtk-snfi: Add snfi sample delay and read latency adjustment

Add snfi sample delay and read latency adjustment which can get
from dts property.

Signed-off-by: Xiangsheng Hou <xiangsheng.hou@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20230201020921.26712-5-xiangsheng.hou@mediatek.com


Signed-off-by: Mark Brown <broonie@kernel.org>