hwc: Alpha downscale on MDP4 is not a hard condition.

Alpha downscaling check should be applied to the full and partial
mdp comp checks rather than as a hard-feature check.

This means we could still have a video going through MDP comp and
the volume bar (lets say) failing the Alpha downscale check.

Change-Id: I6a47057e826668f7f19e20b6d0a548fffa349de2
diff --git a/libhwcomposer/hwc_mdpcomp.cpp b/libhwcomposer/hwc_mdpcomp.cpp
index 4561546..6977564 100644
--- a/libhwcomposer/hwc_mdpcomp.cpp
+++ b/libhwcomposer/hwc_mdpcomp.cpp
@@ -363,10 +363,6 @@
         ALOGD_IF( isDebug(),"%s: External Display connection is pending",
                   __FUNCTION__);
         ret = false;
-    } else if(ctx->listStats[mDpy].needsAlphaScale
-       && ctx->mMDP.version < qdutils::MDSS_V5) {
-        ALOGD_IF(isDebug(), "%s: frame needs alpha downscaling",__FUNCTION__);
-        ret = false;
     } else if(ctx->isPaddingRound) {
         ctx->isPaddingRound = false;
         ALOGD_IF(isDebug(), "%s: padding round",__FUNCTION__);
@@ -400,6 +396,12 @@
         return false;
     }
 
+    if(ctx->listStats[mDpy].needsAlphaScale
+       && ctx->mMDP.version < qdutils::MDSS_V5) {
+        ALOGD_IF(isDebug(), "%s: frame needs alpha downscaling",__FUNCTION__);
+        return false;
+    }
+
     //MDP composition is not efficient if layer needs rotator.
     for(int i = 0; i < numAppLayers; ++i) {
         // As MDP h/w supports flip operation, use MDP comp only for