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

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/include/configs/Total5200.h b/include/configs/Total5200.h
index 9edf790..2e9a2bc 100644
--- a/include/configs/Total5200.h
+++ b/include/configs/Total5200.h
@@ -149,7 +149,7 @@
 #define CONFIG_PREBOOT	\
 	"setenv stdout serial;setenv stderr serial;" \
 	"echo;" \
-	"echo Type \"run flash_nfs\" to mount root filesystem over NFS;" \
+	"echo Type \\\"run flash_nfs\\\" to mount root filesystem over NFS;" \
 	"echo"
 
 #undef	CONFIG_BOOTARGS