Input: synaptics-rmi4 - follow renaming of SPI "master" to "controller"

In commit 8caab75f ("spi: Generalize SPI "master" to "controller"")
some functions and struct members were renamed. To not break all drivers
compatibility macros were provided.

To be able to remove these compatibility macros push the renaming into
this driver.
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/b88413456c970a97319fa7e505768bf82966541b.1707324794.git.u.kleine-koenig@pengutronix.deSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/input/rmi4/rmi_spi.c

@@ -375,7 +375,7 @@ static int rmi_spi_probe(struct spi_device *spi)
 	struct rmi_device_platform_data *spi_pdata = spi->dev.platform_data;
 	int error;
 
-	if (spi->master->flags & SPI_CONTROLLER_HALF_DUPLEX)
+	if (spi->controller->flags & SPI_CONTROLLER_HALF_DUPLEX)
 		return -EINVAL;
 
 	rmi_spi = devm_kzalloc(&spi->dev, sizeof(struct rmi_spi_xport),