cmd_bmp.c: message about compressed formats is debug info only.

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Anatolij Gustschin <agust@denx.de>
diff --git a/common/cmd_bmp.c b/common/cmd_bmp.c
index f2a48f7..23fc82f 100644
--- a/common/cmd_bmp.c
+++ b/common/cmd_bmp.c
@@ -79,7 +79,7 @@
 		return NULL;
 	}
 
-	puts("Gzipped BMP image detected!\n");
+	debug("Gzipped BMP image detected!\n");
 
 	return bmp;
 }