spi: mediatek: advertise the availability of Dual and Quad mode

this patch advertise the availability of Dual and Quad SPI mode
for ipm design.

Signed-off-by: Qii Wang <qii.wang@mediatek.com>
Signed-off-by: Tim.Kuo <Tim.kuo@mediatek.com>
Link: https://lore.kernel.org/r/20230523112608.10298-1-qii.wang@mediatek.com


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