rtc: st-lpc: Remove struct resource from struct st_rtc

struct resource in struct st_rtc is not used, remove it.

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Link: https://lore.kernel.org/r/20191123091241.1905-1-nobuhiro1.iwamatsu@toshiba.co.jp


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