spi: cadence: revert "Add SPI transfer delays"

The commit 855a40cd ("spi: cadence: Add SPI transfer delays") adds a
delay after each transfer into the driver's transfer_one(). However,
the delay is already done in SPI core. So this commit unnecessarily
doubles the delay amount. Revert this commit.

Signed-off-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20231206145233.74982-1-namcao@linutronix.de


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