rtc: mt6397: Remove unused member dev

Removing the struct member "dev" in mt6397 RTC driver because it's not
initialized and the only usage is for one debugging message.

Also fixed a typo in the error message.
Signed-off-by: Fei Shao <fshao@chromium.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201008093414.1911699-1-fshao@chromium.org

drivers/rtc/rtc-mt6397.c

@@ -31,7 +31,8 @@ static int mtk_rtc_write_trigger(struct mt6397_rtc *rtc)
 					MTK_RTC_POLL_DELAY_US,
 					MTK_RTC_POLL_TIMEOUT);
 	if (ret < 0)
-		dev_err(rtc->dev, "failed to write WRTGE: %d\n", ret);
+		dev_err(rtc->rtc_dev->dev.parent,
+			"failed to write WRTGR: %d\n", ret);
 
 	return ret;
 }

include/linux/mfd/mt6397/rtc.h

@@ -72,7 +72,6 @@ struct mtk_rtc_data {
 };
 
 struct mt6397_rtc {
-	struct device           *dev;
 	struct rtc_device       *rtc_dev;
 
 	/* Protect register access from multiple tasks */