bootstage: Make use of BOOTSTAGE_ID_RUN_OS in show_boot_progress()

This changes the number 15 as used in boot_stage_progress() to use the
new name provided for it. This is a separate patch because it touches
so many files.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/board/ti/beagle/beagle.c b/board/ti/beagle/beagle.c
index c09c833..114ab7e 100644
--- a/board/ti/beagle/beagle.c
+++ b/board/ti/beagle/beagle.c
@@ -485,7 +485,7 @@
 /* Call usb_stop() before starting the kernel */
 void show_boot_progress(int val)
 {
-	if(val == 15)
+	if (val == BOOTSTAGE_ID_RUN_OS)
 		usb_stop();
 }