xpl: Rename spl_phase() to xpl_phase()

Rename this function to indicate that it refers to any xPL phase.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/boot/fdt_simplefb.c b/boot/fdt_simplefb.c
index 5341554..71b833e 100644
--- a/boot/fdt_simplefb.c
+++ b/boot/fdt_simplefb.c
@@ -27,7 +27,7 @@
 	struct udevice *dev;
 	int ret;
 
-	if (IS_ENABLED(CONFIG_SPL_VIDEO_HANDOFF) && spl_phase() > PHASE_SPL) {
+	if (IS_ENABLED(CONFIG_SPL_VIDEO_HANDOFF) && xpl_phase() > PHASE_SPL) {
 		struct video_handoff *ho;
 
 		ho = bloblist_find(BLOBLISTT_U_BOOT_VIDEO, sizeof(*ho));