rtc: ds1307: Clear OSF flag on DS1388 when setting time

Ensure the OSF flag is cleared on the DS1388 when the clock is set.

Fixes: df11b323 ("rtc: ds1307: handle oscillator failure flags for ds1388 variant")
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20200818013543.4283-1-chris.packham@alliedtelesis.co.nz

drivers/rtc/rtc-ds1307.c

@@ -353,6 +353,10 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
 		regmap_update_bits(ds1307->regmap, DS1340_REG_FLAG,
 				   DS1340_BIT_OSF, 0);
 		break;
+	case ds_1388:
+		regmap_update_bits(ds1307->regmap, DS1388_REG_FLAG,
+				   DS1388_BIT_OSF, 0);
+		break;
 	case mcp794xx:
 		/*
 		 * these bits were cleared when preparing the date/time