rtc: pcf85363: remove useless forward declaration

It is not necessary to forward declare pcf85363_driver as it is not used
before being declared.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-pcf85363.c

@@ -112,8 +112,6 @@
 
 #define NVRAM_SIZE	0x40
 
-static struct i2c_driver pcf85363_driver;
-
 struct pcf85363 {
 	struct rtc_device	*rtc;
 	struct regmap		*regmap;