mx28evk: Allow booting a zImage kernel

Allow booting a zImage kernel.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>

include/configs/mx28evk.h

@@ -67,6 +67,7 @@
 #define CONFIG_CMD_SF
 #define CONFIG_CMD_SPI
 #define CONFIG_CMD_USB
+#define CONFIG_CMD_BOOTZ
 
 /*
  * Memory configurations