beagleboard: add support for xM revision C

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
diff --git a/board/ti/beagle/beagle.h b/board/ti/beagle/beagle.h
index a7401b1..04247cd 100644
--- a/board/ti/beagle/beagle.h
+++ b/board/ti/beagle/beagle.h
@@ -39,6 +39,7 @@
 #define REVISION_C4	0x5
 #define REVISION_XM_A	0x0
 #define REVISION_XM_B	0x1
+#define REVISION_XM_C	0x2
 
 /*
  * IEN  - Input Enable