overlay: Compile MDSS rotator even when headers not present

Change-Id: Ifc74531b6d73ab5d752441d1a0e7d3b0d0d658e0
(cherry picked from commit e76f183710272f02149e003357107c85bc74914b)
diff --git a/liboverlay/mdssRotator.cpp b/liboverlay/mdssRotator.cpp
index 16b866a..52d6e67 100644
--- a/liboverlay/mdssRotator.cpp
+++ b/liboverlay/mdssRotator.cpp
@@ -18,6 +18,10 @@
 #include "overlayUtils.h"
 #include "overlayRotator.h"
 
+#ifndef MDSS_MDP_ROT_ONLY
+#define MDSS_MDP_ROT_ONLY 0x80
+#endif
+
 namespace ovutils = overlay::utils;
 
 namespace overlay {