rtc: ds1511: put ds1511_nvmem_cfg on the stack

Move ds1511_nvmem_cfg to the stack of ds1511_rtc_probe. This results in a
very small code size reduction and make it safer on systems with two
similar RTCs:

   text	   data	    bss	    dec	    hex	filename
   2128	    164	      4	   2296	    8f8	drivers/rtc/rtc-ds1511.o.before
   2175	    100	      4	   2279	    8e7	drivers/rtc/rtc-ds1511.o.after
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-ds1511.c

@@ -422,20 +422,20 @@ static int ds1511_nvram_write(void *priv, unsigned int pos, void *buf,
 	return 0;
 }
 
-static struct nvmem_config ds1511_nvmem_cfg = {
+static int ds1511_rtc_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct rtc_plat_data *pdata;
+	int ret = 0;
+	struct nvmem_config ds1511_nvmem_cfg = {
 		.name = "ds1511_nvram",
 		.word_size = 1,
 		.stride = 1,
 		.size = DS1511_RAM_MAX,
 		.reg_read = ds1511_nvram_read,
 		.reg_write = ds1511_nvram_write,
-};
-
-static int ds1511_rtc_probe(struct platform_device *pdev)
-{
-	struct resource *res;
-	struct rtc_plat_data *pdata;
-	int ret = 0;
+		.priv = &pdev->dev,
+	};
 
 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
@@ -478,7 +478,6 @@ static int ds1511_rtc_probe(struct platform_device *pdev)
 
 	pdata->rtc->ops = &ds1511_rtc_ops;
 
-	ds1511_nvmem_cfg.priv = &pdev->dev;
 	pdata->rtc->nvram_old_abi = true;
 
 	ret = rtc_register_device(pdata->rtc);