Correct SPL use of VIDEO_BPP16

This converts 1 usage of this option to the non-SPL form, since there is
no SPL_VIDEO_BPP16 defined in Kconfig

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/video/video-uclass.c b/drivers/video/video-uclass.c
index 0ce376c..f36970e 100644
--- a/drivers/video/video-uclass.c
+++ b/drivers/video/video-uclass.c
@@ -196,7 +196,7 @@
 {
 	switch (priv->bpix) {
 	case VIDEO_BPP16:
-		if (CONFIG_IS_ENABLED(VIDEO_BPP16)) {
+		if (IS_ENABLED(CONFIG_VIDEO_BPP16)) {
 			return ((colours[idx].r >> 3) << 11) |
 			       ((colours[idx].g >> 2) <<  5) |
 			       ((colours[idx].b >> 3) <<  0);