spi: spi-mtk-nor: improve device table for adding more capabilities

Define a structure for adding more capabilities.
Add a item extra_dummy_bit for new SoCs, due to design changed.

Signed-off-by: Guochun Mao <guochun.mao@mediatek.com>
Signed-off-by: Zhen Zhang <zhen.zhang@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20220118142820.2729-3-guochun.mao@mediatek.com


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