rtc: pcf8523: Remove struct pcf8523

struct pcf8523 is referenced only by pcf8523_probe(). And member variable in
this is not referenced by any function. Remove struct pcf8523.

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Link: https://lore.kernel.org/r/20191123090838.1619-1-nobuhiro1.iwamatsu@toshiba.co.jp


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