MX51: vision2: add MACH_TYPE in config file

Add the MACH type to the configuration file. Maybe the board
will be not pushed into linux ML, but it remains compatible
with older kernels.

Signed-off-by: Stefano Babic <sbabic@denx.de>
diff --git a/include/configs/vision2.h b/include/configs/vision2.h
index 2d020ca..29ef541 100644
--- a/include/configs/vision2.h
+++ b/include/configs/vision2.h
@@ -41,6 +41,9 @@
 #define CONFIG_INITRD_TAG
 #define CONFIG_BOARD_LATE_INIT
 
+#ifndef MACH_TYPE_TTC_VISION2
+#define MACH_TYPE_TTC_VISION2	2775
+#endif
 #define CONFIG_MACH_TYPE	MACH_TYPE_TTC_VISION2
 
 /*