spi: hisi-sfc-v3xx: Fix a typo ("duall")

Simple typo, simple fix.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20221103190052.915755-1-j.neuschaefer@gmx.net


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