spi: axi-spi-engine: implement xfer->cs_change_delay

This adds handling of xfer->cs_change_delay to the AXI SPI Engine
driver.

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-v1-6-063672323fce@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: dlech

drivers/spi/spi-axi-spi-engine.c

@@ -265,6 +265,10 @@ static void spi_engine_compile_message(struct spi_message *msg, bool dry,
 				if (!xfer->cs_off)
 					spi_engine_gen_cs(p, dry, spi, false);
 
+				spi_engine_gen_sleep(p, dry, spi_delay_to_ns(
+					&xfer->cs_change_delay, xfer),
+					xfer->effective_speed_hz);
+
 				if (!list_next_entry(xfer, transfer_list)->cs_off)
 					spi_engine_gen_cs(p, dry, spi, true);
 			}