ARM: imx6: nitrogen6x: Enable CONFIG_SYS_GENERIC_BOARD

Enable CONFIG_SYS_GENERIC_BOARD, so that we get rid of the following warning on
boot:

"Warning: Your board does not use generic board. Please read
doc/README.generic-board and take action. Boards not
upgraded by the late 2014 may break or be removed."

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
diff --git a/include/configs/nitrogen6x.h b/include/configs/nitrogen6x.h
index 5805a03..b2b17ce 100644
--- a/include/configs/nitrogen6x.h
+++ b/include/configs/nitrogen6x.h
@@ -24,6 +24,7 @@
 #define CONFIG_SETUP_MEMORY_TAGS
 #define CONFIG_INITRD_TAG
 #define CONFIG_REVISION_TAG
+#define CONFIG_SYS_GENERIC_BOARD
 
 /* Size of malloc() pool */
 #define CONFIG_SYS_MALLOC_LEN		(10 * 1024 * 1024)