rtc: tx4939: set range

The TX4939 RTC is a 48bit counter that counts two on every clock edge of
32.768 KHz oscillator clock so it counts 32bit seconds.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-tx4939.c

@@ -276,6 +276,7 @@ static int __init tx4939_rtc_probe(struct platform_device *pdev)
 
 	rtc->ops = &tx4939_rtc_ops;
 	rtc->nvram_old_abi = true;
+	rtc->range_max = U32_MAX;
 
 	pdata->rtc = rtc;