rtc: ds1305: call rtc_nvmem_register()

Call rtc_nvmem_register instead of letting the core do it and stop using
the nvmem_config member of struct rtc_device.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-ds1305.c

@@ -703,15 +703,15 @@ static int ds1305_probe(struct spi_device *spi)
 	ds1305->rtc->ops = &ds1305_ops;
 
 	ds1305_nvmem_cfg.priv = ds1305;
-	ds1305->rtc->nvmem_config = &ds1305_nvmem_cfg;
 	ds1305->rtc->nvram_old_abi = true;
-
 	status = rtc_register_device(ds1305->rtc);
 	if (status) {
 		dev_dbg(&spi->dev, "register rtc --> %d\n", status);
 		return status;
 	}
 
+	rtc_nvmem_register(ds1305->rtc, &ds1305_nvmem_cfg);
+
 	/* Maybe set up alarm IRQ; be ready to handle it triggering right
 	 * away.  NOTE that we don't share this.  The signal is active low,
 	 * and we can't ack it before a SPI message delay.  We temporarily