NFC: trf7970a: Only check 'en2-rf-quirk' if EN2 is specified

The quirk indicated by the 'en2-rf-quirk' device tree property
is only relevant when there is a GPIO connected to the EN2 pin
of the trf7970a. This means we should only check for 'en2-rf-quirk'
when EN2 is specified in the 'ti,enable-gpios' property of the
device tree.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/nfc/trf7970a.c

@@ -2070,6 +2070,9 @@ static int trf7970a_probe(struct spi_device *spi)
 			dev_err(trf->dev, "Can't request EN2 GPIO: %d\n", ret);
 			return ret;
 		}
+
+		if (of_property_read_bool(np, "en2-rf-quirk"))
+			trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
 	}
 
 	of_property_read_u32(np, "clock-frequency", &clk_freq);
@@ -2081,9 +2084,6 @@ static int trf7970a_probe(struct spi_device *spi)
 		return -EINVAL;
 	}
 
-	if (of_property_read_bool(np, "en2-rf-quirk"))
-		trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
-
 	ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
 			trf7970a_irq, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 			"trf7970a", trf);