hwc: mdpcomp: Restructure for 4kx2k displays

Restructure MDPComp class for 4kx2k displays.
Cleanup MDPComp class to remove unused stuff and formatting.
Add a MDPCompLowRes class for current functionality.
Add a hollow MDPCompHighRes class for future.

Change-Id: I343540e712d31ca907257a73b49567578f49d5f7
diff --git a/libhwcomposer/hwc_utils.cpp b/libhwcomposer/hwc_utils.cpp
index 7ae4afd..9882975 100644
--- a/libhwcomposer/hwc_utils.cpp
+++ b/libhwcomposer/hwc_utils.cpp
@@ -69,6 +69,7 @@
     ctx->mExtDisplay = new ExternalDisplay(ctx);
     for (uint32_t i = 0; i < HWC_NUM_DISPLAY_TYPES; i++)
         ctx->mLayerCache[i] = new LayerCache();
+    ctx->mMDPComp = MDPComp::getObject(ctx->dpyAttr[HWC_DISPLAY_PRIMARY].xres);
     MDPComp::init(ctx);
 
     pthread_mutex_init(&(ctx->vstate.lock), NULL);
@@ -105,6 +106,11 @@
         }
     }
 
+    if(ctx->mMDPComp) {
+        delete ctx->mMDPComp;
+        ctx->mMDPComp = NULL;
+    }
+
     pthread_mutex_destroy(&(ctx->vstate.lock));
     pthread_cond_destroy(&(ctx->vstate.cond));
 }