spi: spi-falcon: remove check for 'delay_usecs'

The 'delay_usecs' field is being removed from the spi_transfer struct.
This change removes it from the SPI Falcon driver.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210308145502.1075689-8-aardelean@deviqon.com


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