make show_boot_progress () weak.

Signed-off-by: Heiko Schocher <hs@denx.de>
diff --git a/lib_blackfin/post.c b/lib_blackfin/post.c
index 0e76026..7c9478d 100644
--- a/lib_blackfin/post.c
+++ b/lib_blackfin/post.c
@@ -132,9 +132,7 @@
 				post_log("PASSED\n");
 			else {
 				post_log("FAILED\n");
-#ifdef CONFIG_SHOW_BOOT_PROGRESS
-				show_boot_progress(-31);
-#endif
+				show_boot_progress (-31);
 			}
 		}
 	}
@@ -245,9 +243,7 @@
 		} else {
 			if ((*test->test) (flags) != 0) {
 				post_log("FAILED\n");
-#ifdef CONFIG_SHOW_BOOT_PROGRESS
-				show_boot_progress(-32);
-#endif
+				show_boot_progress (-32);
 			} else
 				post_log("PASSED\n");
 		}