imx6: move standard ATAG configs to mx6_common.h

Define the standard ATAG consfigs in mx6_common.

Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Reviewed-by: Tom Rini <trini at konsulko.com>
diff --git a/include/configs/gw_ventana.h b/include/configs/gw_ventana.h
index 41f9c9c..89c9c84 100644
--- a/include/configs/gw_ventana.h
+++ b/include/configs/gw_ventana.h
@@ -36,12 +36,8 @@
 
 #define CONFIG_MACH_TYPE	4520   /* Gateworks Ventana Platform */
 
-/* ATAGs */
-#define CONFIG_CMDLINE_TAG
-#define CONFIG_SETUP_MEMORY_TAGS
-#define CONFIG_INITRD_TAG
+/* Serial ATAG */
 #define CONFIG_SERIAL_TAG
-#define CONFIG_REVISION_TAG
 
 /* Size of malloc() pool */
 #define CONFIG_SYS_MALLOC_LEN		(10 * SZ_1M)