rtc: m41t80: Switch to use %ptR

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c
index a391389..ebf50b1 100644
--- a/drivers/rtc/rtc-m41t80.c
+++ b/drivers/rtc/rtc-m41t80.c
@@ -942,11 +942,7 @@ static int m41t80_probe(struct i2c_client *client,
 		if (m41t80_data->features & M41T80_FEATURE_HT) {
 			m41t80_rtc_read_time(&client->dev, &tm);
 			dev_info(&client->dev, "HT bit was set!\n");
-			dev_info(&client->dev,
-				 "Power Down at %04i-%02i-%02i %02i:%02i:%02i\n",
-				 tm.tm_year + 1900,
-				 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
-				 tm.tm_min, tm.tm_sec);
+			dev_info(&client->dev, "Power Down at %ptR\n", &tm);
 		}
 		rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_HOUR,
 					       rc & ~M41T80_ALHOUR_HT);