mx25pdk: Allow booting a zImage kernel

Allow booting a zImage kernel.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
diff --git a/include/configs/mx25pdk.h b/include/configs/mx25pdk.h
index 0bb3579..a4bd8b0 100644
--- a/include/configs/mx25pdk.h
+++ b/include/configs/mx25pdk.h
@@ -87,6 +87,7 @@
 
 /* U-Boot commands */
 #include <config_cmd_default.h>
+#define CONFIG_CMD_BOOTZ
 #define CONFIG_CMD_CACHE
 #define CONFIG_CMD_MMC
 #define CONFIG_CMD_EXT2