device property: fwnode_property_read_string_array() may return -EILSEQ

fwnode_property_read_string_array() may return -EILSEQ through
of_property_read_string_array(). Document this.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/base/property.c

@@ -591,7 +591,7 @@ static int __fwnode_property_read_string(struct fwnode_handle *fwnode,
  *         %0 if the property was found (success),
  *	   %-EINVAL if given arguments are not valid,
  *	   %-ENODATA if the property does not have a value,
- *	   %-EPROTO if the property is not an array of strings,
+ *	   %-EPROTO or %-EILSEQ if the property is not an array of strings,
  *	   %-EOVERFLOW if the size of the property is not as expected,
  *	   %-ENXIO if no suitable firmware interface is present.
  */