hwc: Add API to find if a display is split

A display could be split if its dimensions exceed 2048 or in case
of primary if we make it so via device tree property.

Add an API to find if a display is split. Use this API instead of
going through a set of conditions in various use cases.
Rename the HighRes, LowRes objects to a more appropriate Split and
NonSplit respectively

Change-Id: Id847c2bf36ea9250e1cdbc0259fdec64bd124537
diff --git a/libhwcomposer/hwc_uevents.cpp b/libhwcomposer/hwc_uevents.cpp
index 5590798..a44924b 100644
--- a/libhwcomposer/hwc_uevents.cpp
+++ b/libhwcomposer/hwc_uevents.cpp
@@ -48,11 +48,8 @@
 
 static void setup(hwc_context_t* ctx, int dpy)
 {
-    const int rSplit = 0; //Even split for external if at all
-    ctx->mFBUpdate[dpy] = IFBUpdate::getObject(ctx->dpyAttr[dpy].xres,
-            rSplit, dpy);
-    ctx->mMDPComp[dpy] =  MDPComp::getObject(ctx->dpyAttr[dpy].xres,
-            rSplit, dpy);
+    ctx->mFBUpdate[dpy] = IFBUpdate::getObject(ctx, dpy);
+    ctx->mMDPComp[dpy] =  MDPComp::getObject(ctx, dpy);
     int compositionType =
                 qdutils::QCCompositionType::getInstance().getCompositionType();
     if (compositionType & (qdutils::COMPOSITION_TYPE_DYN |