spi: dw: Use an explicit set_cs assignment

Simplify the dw_spi_add_host() method a bit by replacing the currently
implemented default set_cs callback setting up and later having it
overwritten by a custom function with direct if-else-based callback
assignment.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20201007235511.4935-2-Sergey.Semin@baikalelectronics.ruSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-dw-core.c

@@ -477,7 +477,10 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
 	master->num_chipselect = dws->num_cs;
 	master->setup = dw_spi_setup;
 	master->cleanup = dw_spi_cleanup;
-	master->set_cs = dw_spi_set_cs;
+	if (dws->set_cs)
+		master->set_cs = dws->set_cs;
+	else
+		master->set_cs = dw_spi_set_cs;
 	master->transfer_one = dw_spi_transfer_one;
 	master->handle_err = dw_spi_handle_err;
 	master->max_speed_hz = dws->max_freq;
@@ -486,9 +489,6 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
 	master->flags = SPI_MASTER_GPIO_SS;
 	master->auto_runtime_pm = true;
 
-	if (dws->set_cs)
-		master->set_cs = dws->set_cs;
-
 	/* Get default rx sample delay */
 	device_property_read_u32(dev, "rx-sample-delay-ns",
 				 &dws->def_rx_sample_dly_ns);