rtc: pcf8563: clear RTC_FEATURE_ALARM if no irq

If there is no IRQ hooked up, clear RTC_FEATURE_ALARM to make the core
ensure that userspace is made aware that alarms are not supported.
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Link: https://lore.kernel.org/r/20220301131220.4011810-1-vincent.whitchurch@axis.comSigned-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-pcf8563.c

@@ -567,6 +567,8 @@ static int pcf8563_probe(struct i2c_client *client)
 								client->irq);
 			return err;
 		}
+	} else {
+		clear_bit(RTC_FEATURE_ALARM, pcf8563->rtc->features);
 	}
 
 	err = devm_rtc_register_device(pcf8563->rtc);