bootstage: Eliminate when not enabled

When we do not have bootstage enabled, rather than include an empty
dummy function, we just don't reference it.  This saves us space in some
tight builds.  This also shows a few cases where show_boot_progress was
incorrectly guarded before.

Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/board/st/stv0991/stv0991.c b/board/st/stv0991/stv0991.c
index 3b0de82..57ca9f6 100644
--- a/board/st/stv0991/stv0991.c
+++ b/board/st/stv0991/stv0991.c
@@ -37,7 +37,7 @@
 };
 #endif
 
-#ifdef CONFIG_SHOW_BOOT_PROGRESS
+#if CONFIG_IS_ENABLED(BOOTSTAGE)
 void show_boot_progress(int progress)
 {
 	printf("%i\n", progress);