rtc: pcf8523: Fix GCC 12 warning

When building with automatic stack variable initialization, GCC 12
complains about variables defined outside of switch case statements.
Move variables outside the switch, which silences warnings:

./drivers/rtc/rtc-pcf8523.c:284:20: error: statement will never be executed [-Werror=switch-unreachable]
  284 |                 u8 mode;
      |

./drivers/rtc/rtc-pcf8523.c:245:21: error: statement will never be executed [-Werror=switch-unreachable]
  245 |                 u32 value;
      |                     ^~~~~
Signed-off-by: Victor Erminpour <victor.erminpour@oracle.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/1644453027-886-1-git-send-email-victor.erminpour@oracle.com

drivers/rtc/rtc-pcf8523.c

@@ -240,9 +240,9 @@ static int pcf8523_param_get(struct device *dev, struct rtc_param *param)
 {
 	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
 	int ret;
+	u32 value;
 
 	switch(param->param) {
-		u32 value;
 
 	case RTC_PARAM_BACKUP_SWITCH_MODE:
 		ret = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL3, &value);
@@ -279,9 +279,9 @@ static int pcf8523_param_get(struct device *dev, struct rtc_param *param)
 static int pcf8523_param_set(struct device *dev, struct rtc_param *param)
 {
 	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	u8 mode;
 
 	switch(param->param) {
-		u8 mode;
 	case RTC_PARAM_BACKUP_SWITCH_MODE:
 		switch (param->uvalue) {
 		case RTC_BSM_DISABLED: