spi: axi-spi-engine: remove xfer arg from spi_engine_gen_sleep()

This replaces the xfer parameter of spi_engine_gen_sleep() in the AXI
SPI Engine driver with parameters for the delay in nanoseconds and the
SPI SCLK rate. This will allow this function to be used by callers in
the future that do not have a spi_transfer struct.

Signed-off-by: David Lechner <dlechner@baylibre.com>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20231204-axi-spi-engine-series-2-v1-5-063672323fce@baylibre.com


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