all platforms: make show_boot_progress() work again

Signed-off-by: Heiko Schocher <hs@denx.de>

include/common.h

@@ -688,7 +688,7 @@ int	pcmcia_init (void);
 /*
  * Board-specific Platform code can reimplement show_boot_progress () if needed
  */
-void __attribute__((weak)) show_boot_progress (int val);
+void show_boot_progress(int val);
 
 #ifdef CONFIG_INIT_CRITICAL
 #error CONFIG_INIT_CRITICAL is deprecated!