Fix this build error when PM_SLEEP is not selected:

drivers/rtc/rtc-mt2712.c:412:10: error: ‘mt2712_pm_ops’ undeclared here (not in a function); did you mean ‘mt2712_rtc_ops’?
  412 |   .pm = &mt2712_pm_ops,
      |          ^~~~~~~~~~~~~

Link: https://lore.kernel.org/r/20200317143421.9551-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

This add support for the MediaTek MT2712 RTC. It was SoC based RTC, but
had different architecture compared with MT7622 RTC.

Signed-off-by: Ran Bi <ran.bi@mediatek.com>
Link: https://lore.kernel.org/r/20200226051303.22560-3-ran.bi@mediatek.com
Link: https://lore.kernel.org/r/20200316104701.209293-2-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>