topic_miami: Remove CONFIG_CMD_BOOTZ undef

CONFIG_CMD_BOOTZ option has been converted to defconfig, so there
is no need to undefine it in board config file anymore.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
diff --git a/include/configs/topic_miami.h b/include/configs/topic_miami.h
index d538080..400a7fc 100644
--- a/include/configs/topic_miami.h
+++ b/include/configs/topic_miami.h
@@ -134,7 +134,6 @@
 #undef CONFIG_DISPLAY_BOARDINFO
 
 /* Further tweaks to reduce image size */
-#undef CONFIG_CMD_BOOTZ
 #undef CONFIG_CMD_NET
 
 #endif /* __CONFIG_TOPIC_MIAMI_H */