rtc: at91rm9200: Mark driver struct with __refdata to prevent section mismatch warning

As described in the added code comment, a reference to .exit.text is ok
for drivers registered via module_platform_driver_probe(). Make this
explicit to prevent a section mismatch warning.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231002080529.2535610-3-u.kleine-koenig@pengutronix.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Author: Uwe Kleine-König

drivers/rtc/rtc-at91rm9200.c

@@ -635,7 +635,13 @@ static int at91_rtc_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume);
 
-static struct platform_driver at91_rtc_driver = {
+/*
+ * at91_rtc_remove() lives in .exit.text. For drivers registered via
+ * module_platform_driver_probe() this is ok because they cannot get unbound at
+ * runtime. So mark the driver struct with __refdata to prevent modpost
+ * triggering a section mismatch warning.
+ */
+static struct platform_driver at91_rtc_driver __refdata = {
 	.remove		= __exit_p(at91_rtc_remove),
 	.shutdown	= at91_rtc_shutdown,
 	.driver		= {