regulator: tps65132: Stop parsing DT when gpio is not found

In case of a missing (optional) gpio don't fall through up to
"ti,active-discharge-time-us" due to
devm_fwnode_get_index_gpiod_from_child() returning NULL (since
gpiod_get_from_of_node() returned NULL) but rather indicate success as
intended.

This makes the driver probe correctly when e.g. only the enable gpio is
given.

Signed-off-by: Guido Günther <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/tps65132-regulator.c

···
 
 	rpdata->en_gpiod = devm_fwnode_get_index_gpiod_from_child(tps->dev,
 					"enable", 0, &np->fwnode, 0, "enable");
-	if (IS_ERR(rpdata->en_gpiod)) {
+	if (IS_ERR_OR_NULL(rpdata->en_gpiod)) {
 		ret = PTR_ERR(rpdata->en_gpiod);
 
 		/* Ignore the error other than probe defer */
···
 	rpdata->act_dis_gpiod = devm_fwnode_get_index_gpiod_from_child(
 					tps->dev, "active-discharge", 0,
 					&np->fwnode, 0, "active-discharge");
-	if (IS_ERR(rpdata->act_dis_gpiod)) {
+	if (IS_ERR_OR_NULL(rpdata->act_dis_gpiod)) {
 		ret = PTR_ERR(rpdata->act_dis_gpiod);
 
 		/* Ignore the error other than probe defer */