mx23evk: Set default environment to use zImage

Change the default environment to use zImage instead of uImage, this
requires changes to the default environment to load a file named
zImage instead of uImage, and to use the 'bootz' command instead of
'bootm' when booting the kernel.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>

include/configs/mx23evk.h

@@ -84,7 +84,7 @@
 		"fi ; "	\
 		"fi\0" \
 	"script=boot.scr\0"	\
-	"uimage=uImage\0" \
+	"image=zImage\0" \
 	"console=ttyAMA0\0" \
 	"fdt_file=imx23-evk.dtb\0" \
 	"fdt_addr=0x41000000\0" \
@@ -98,22 +98,22 @@
 		"fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${script};\0" \
 	"bootscript=echo Running bootscript from mmc ...; "	\
 		"source\0" \
-	"loaduimage=fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${uimage}\0" \
+	"loadimage=fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${image}\0" \
 	"loadfdt=fatload mmc ${mmcdev}:${mmcpart} ${fdt_addr} ${fdt_file}\0" \
 	"mmcboot=echo Booting from mmc ...; " \
 		"run mmcargs; " \
 		"if test ${boot_fdt} = yes || test ${boot_fdt} = try; then " \
 			"if run loadfdt; then " \
-				"bootm ${loadaddr} - ${fdt_addr}; " \
+				"bootz ${loadaddr} - ${fdt_addr}; " \
 			"else " \
 				"if test ${boot_fdt} = try; then " \
-					"bootm; " \
+					"bootz; " \
 				"else " \
 					"echo WARN: Cannot load the DT; " \
 				"fi; " \
 			"fi; " \
 		"else " \
-			"bootm; " \
+			"bootz; " \
 		"fi;\0"
 
 #define CONFIG_BOOTCOMMAND \
@@ -121,7 +121,7 @@
 		"if run loadbootscript; then " \
 			"run bootscript; " \
 		"else " \
-			"if run loaduimage; then " \
+			"if run loadimage; then " \
 				"run mmcboot; " \
 			"else " \
 				"echo ERR: Fail to boot from MMC; " \