rename CONFIG_CMD_ENV to CONFIG_CMD_SAVEENV

The CONFIG_CMD_ENV option controls enablement of the `saveenv` command
rather than a generic "env" command, or anything else related to the
environment.  So, let's make sure the define is named accordingly.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/include/configs/mpc7448hpc2.h b/include/configs/mpc7448hpc2.h
index 483bc53..a1783b2 100644
--- a/include/configs/mpc7448hpc2.h
+++ b/include/configs/mpc7448hpc2.h
@@ -163,7 +163,7 @@
 #define CONFIG_CMD_SDRAM
 #define CONFIG_CMD_EEPROM
 #define CONFIG_CMD_FLASH
-#define CONFIG_CMD_ENV
+#define CONFIG_CMD_SAVEENV
 #define CONFIG_CMD_BSP
 #define CONFIG_CMD_DHCP
 #define CONFIG_CMD_PING