spi: spi-falcon: extend warning to `delay` as well

The WARN_ON macro prints a warning in syslog if `delay_usecs` is non-zero.
However, with the new intermediate `delay`, the warning should also be
printed.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-18-alexandru.ardelean@analog.com


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