rtc: pcf2127: remove useless check

This check is only useful when introducing support for a new RTC in the
driver. Cut down the number of strings in th driver.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Alexandre Belloni <[e-mail]>

drivers/rtc/rtc-pcf2127.c

···
 		return ret;
 	}
 
-	/* TS input pin driven to GND detection is supported by all variants.
-	 * Make sure that interrupt bit is defined.
-	 */
-	if (pcf2127->cfg->ts[ts_id].gnd_detect_bit == 0) {
-		dev_err(dev, "%s: tamper detection to GND configuration invalid\n",
-			__func__);
-		return -EINVAL;
-	}
-
 	/*
 	 * Enable interrupt generation when TSF timestamp flag is set.
 	 * Interrupt signals are open-drain outputs and can be left floating if