Fix quoting problem (preboot setting) in many board config files.

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/include/configs/DB64360.h b/include/configs/DB64360.h
index db2e96c..eef216d 100644
--- a/include/configs/DB64360.h
+++ b/include/configs/DB64360.h
@@ -169,7 +169,7 @@
 
 
 #undef	CONFIG_BOOTARGS
-/*#define CONFIG_PREBOOT	"echo;echo Type \"run flash_nfs\" to mount root filesystem over NFS;echo" */
+/*#define CONFIG_PREBOOT	"echo;echo Type \\\"run flash_nfs\\\" to mount root filesystem over NFS;echo" */
 
 /* ronen - autoboot using tftp */
 #if (CONFIG_BOOTDELAY >= 0)