exynos: Update environment macros a bit

Rework the default environment a bit to not use non-standard
CONFIG_ENV_... names and similar one-off CONFIG names.

Cc: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
diff --git a/include/configs/exynos4-common.h b/include/configs/exynos4-common.h
index 5e2aca3..2ca14d0 100644
--- a/include/configs/exynos4-common.h
+++ b/include/configs/exynos4-common.h
@@ -32,7 +32,7 @@
 #define CONFIG_USB_GADGET_DWC2_OTG_PHY
 
 /* Common environment variables */
-#define CONFIG_EXTRA_ENV_ITB \
+#define ENV_ITB \
 	"loadkernel=load mmc ${mmcbootdev}:${mmcbootpart} ${kerneladdr} " \
 		"${kernelname}\0" \
 	"loadinitrd=load mmc ${mmcbootdev}:${mmcbootpart} ${initrdaddr} " \