rtc: rv8803: avoid clearing RV8803_FLAG_V2F in RTC_VL_CLR

Stop clearing RV8803_FLAG_V2F in RTC_VL_CLR because it is a disservice to
userspace as it removes the important information that the RTC data is
invalid. This may lead userspace to set an invalid system time later on.

Link: https://lore.kernel.org/r/20191214220259.621996-15-alexandre.belloni@bootlin.comSigned-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-rv8803.c

@@ -440,7 +440,7 @@ static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 			return flags;
 		}
 
-		flags &= ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F);
+		flags &= ~RV8803_FLAG_V1F;
 		ret = rv8803_write_reg(client, RV8803_FLAG, flags);
 		mutex_unlock(&rv8803->flags_lock);
 		if (ret)