rtc: rv8803: 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-rv8803.c

@@ -591,12 +591,13 @@ static int rv8803_probe(struct i2c_client *client,
 	rv8803->nvmem_cfg.priv = client;
 
 	rv8803->rtc->ops = &rv8803_rtc_ops;
-	rv8803->rtc->nvmem_config = &rv8803->nvmem_cfg;
 	rv8803->rtc->nvram_old_abi = true;
 	err = rtc_register_device(rv8803->rtc);
 	if (err)
 		return err;
 
+	rtc_nvmem_register(rv8803->rtc, &rv8803->nvmem_cfg);
+
 	err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA);
 	if (err)
 		return err;