ASoC: da7219-aad: fix usage of device_get_named_child_node()

The documentation for device_get_named_child_node() mentions this
important point:

"
The caller is responsible for calling fwnode_handle_put() on the
returned fwnode pointer.
"

Add fwnode_handle_put() to avoid a leaked reference.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20240426153033.38500-1-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/da7219-aad.c

@@ -671,8 +671,10 @@ static struct da7219_aad_pdata *da7219_aad_fw_to_pdata(struct device *dev)
 		return NULL;
 
 	aad_pdata = devm_kzalloc(dev, sizeof(*aad_pdata), GFP_KERNEL);
-	if (!aad_pdata)
+	if (!aad_pdata) {
+		fwnode_handle_put(aad_np);
 		return NULL;
+	}
 
 	aad_pdata->irq = i2c->irq;
 
@@ -753,6 +755,8 @@ static struct da7219_aad_pdata *da7219_aad_fw_to_pdata(struct device *dev)
 	else
 		aad_pdata->adc_1bit_rpt = DA7219_AAD_ADC_1BIT_RPT_1;
 
+	fwnode_handle_put(aad_np);
+
 	return aad_pdata;
 }