Correct SPL use of ATMEL_PIO4

This converts 1 usage of this option to the non-SPL form, since there is
no SPL_ATMEL_PIO4 defined in Kconfig

Reviewed-by: Eugen Hristev <eugen.hristev@collabora.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/pinctrl/pinctrl-at91-pio4.c b/drivers/pinctrl/pinctrl-at91-pio4.c
index 50e3dd4..84b3986 100644
--- a/drivers/pinctrl/pinctrl-at91-pio4.c
+++ b/drivers/pinctrl/pinctrl-at91-pio4.c
@@ -271,7 +271,7 @@
 	ofnode node = dev_ofnode(dev);
 	struct atmel_pinctrl_data *priv = (struct atmel_pinctrl_data *)dev_get_driver_data(dev);
 
-	if (!CONFIG_IS_ENABLED(ATMEL_PIO4))
+	if (!IS_ENABLED(CONFIG_ATMEL_PIO4))
 		return 0;
 
 	/* Obtain a handle to the GPIO driver */