rtc: imxdi: Convert to a DT-only driver

i.MX has been converted to a DT-only platform, so make the driver
depend on OF, remove the CONFIG_OF ifdefery and remove of_match_ptr().

Signed-off-by: Fabio Estevam <[e-mail]>
Signed-off-by: Alexandre Belloni <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/rtc/Kconfig

···
 config RTC_DRV_IMXDI
 	tristate "Freescale IMX DryIce Real Time Clock"
 	depends on ARCH_MXC
+	depends on OF
 	help
 	   Support for Freescale IMX DryIce RTC
 

drivers/rtc/rtc-imxdi.c

···
 	return 0;
 }
 
-#ifdef CONFIG_OF
 static const struct of_device_id dryice_dt_ids[] = {
 	{ .compatible = "fsl,imx25-rtc" },
 	{ /* sentinel */ }
 };
 
 MODULE_DEVICE_TABLE(of, dryice_dt_ids);
-#endif
 
 static struct platform_driver dryice_rtc_driver = {
 	.driver = {
 		   .name = "imxdi_rtc",
-		   .of_match_table = of_match_ptr(dryice_dt_ids),
+		   .of_match_table = dryice_dt_ids,
 		   },
 	.remove = __exit_p(dryice_rtc_remove),
 };