overlay : Rely on 8x16 pipe strategy for 8x39.

Since both has same number of pipes with similar
features like scaling capabilities, for now rely on 8x16.

Change-Id: Ief51bb5c70d8aef7dca3d791f8b4d62a4c5392ff
diff --git a/liboverlay/overlay.h b/liboverlay/overlay.h
index 455f547..e8672a7 100644
--- a/liboverlay/overlay.h
+++ b/liboverlay/overlay.h
@@ -170,6 +170,7 @@
     /* Helpers that enfore target specific policies while returning pipes */
     utils::eDest getPipe_8x26(const PipeSpecs& pipeSpecs);
     utils::eDest getPipe_8x16(const PipeSpecs& pipeSpecs);
+    utils::eDest getPipe_8x39(const PipeSpecs& pipeSpecs);
 
     /* Returns the scalar object */
     static scale::Scale *getScalar();
@@ -317,7 +318,8 @@
 
 inline bool Overlay::isUIScalingOnExternalSupported() {
     if(qdutils::MDPVersion::getInstance().is8x26() or
-       qdutils::MDPVersion::getInstance().is8x16()) {
+       qdutils::MDPVersion::getInstance().is8x16() or
+       qdutils::MDPVersion::getInstance().is8x39()) {
         return false;
     }
     return true;