x86: Rationalise kernel booting logic and bootstage

The 'Starting linux' message appears twice in the code, but both call
through the same place. Unify these and add calls to bootstage to
mark the occasion.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Michael Spang <spang@chromium.org>
Acked-by: Graeme Russ <graeme.russ@gmail.com>
diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
index 1a2f85c..7a914a5 100644
--- a/arch/x86/cpu/cpu.c
+++ b/arch/x86/cpu/cpu.c
@@ -120,6 +120,11 @@
 
 int __weak x86_cleanup_before_linux(void)
 {
+#ifdef CONFIG_BOOTSTAGE_STASH
+	bootstage_stash((void *)CONFIG_BOOTSTAGE_STASH,
+			CONFIG_BOOTSTAGE_STASH_SIZE);
+#endif
+
 	return 0;
 }