MIP405: convert to generic board

Signed-off-by: David Müller <d.mueller@elsoft.ch>
diff --git a/include/configs/MIP405.h b/include/configs/MIP405.h
index 68824fd..147f122 100644
--- a/include/configs/MIP405.h
+++ b/include/configs/MIP405.h
@@ -21,6 +21,8 @@
 
 #define	CONFIG_SYS_TEXT_BASE	0xFFF80000
 
+#define CONFIG_SYS_GENERIC_BOARD
+
 /***********************************************************
  * Note that it may also be a MIP405T board which is a subset of the
  * MIP405