Correct SPL use of SANDBOX

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

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
index bc9c17b..d80281f 100644
--- a/drivers/pinctrl/pinctrl-single.c
+++ b/drivers/pinctrl/pinctrl-single.c
@@ -541,7 +541,7 @@
 	INIT_LIST_HEAD(&priv->gpiofuncs);
 
 	size = pdata->offset + pdata->width / BITS_PER_BYTE;
-	#if (CONFIG_IS_ENABLED(SANDBOX))
+	#if (IS_ENABLED(CONFIG_SANDBOX))
 	priv->sandbox_regs =
 		devm_kzalloc(dev, size * sizeof(*priv->sandbox_regs),
 			     GFP_KERNEL);