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/libhwcomposer/hwc.cpp b/libhwcomposer/hwc.cpp
index 0396c91..79f2886 100644
--- a/libhwcomposer/hwc.cpp
+++ b/libhwcomposer/hwc.cpp
@@ -548,7 +548,8 @@
         if(ctx->mMDP.hasOverlay) {
             supported |= HWC_DISPLAY_VIRTUAL_BIT;
             if(!(qdutils::MDPVersion::getInstance().is8x26() ||
-                        qdutils::MDPVersion::getInstance().is8x16()))
+                        qdutils::MDPVersion::getInstance().is8x16() ||
+                        qdutils::MDPVersion::getInstance().is8x39()))
                 supported |= HWC_DISPLAY_EXTERNAL_BIT;
         }
         value[0] = supported;