lib/prog_loaders.c: remove arch/stages.h include

There's no delcaration used. Remove the include.

Change-Id: I6fa7de6362ca0e92f0d5a7d07f3a224b9f77f709
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/13679
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/lib/prog_loaders.c

@@ -15,7 +15,6 @@
 
 
 #include <stdlib.h>
-#include <arch/stages.h>
 #include <cbfs.h>
 #include <cbmem.h>
 #include <console/console.h>