Limit #ROT-SESSIONS to 4 in LayerRotMap and RotMgr

* Limit the number of rotator sessions to 4 both in
LayerRotMap and RotMgr structures

* Make use of MDPVersion getter fuctions to check
for maxMixerWidth and maxDownScale supported by MDP

Change-Id: I27dac877807fbb4ed6fcb3500a3a318a2ef5d8b2
diff --git a/libqdutils/mdp_version.cpp b/libqdutils/mdp_version.cpp
index 48f7cb7..7aa0469 100644
--- a/libqdutils/mdp_version.cpp
+++ b/libqdutils/mdp_version.cpp
@@ -88,8 +88,8 @@
     mVGPipes = 0;
     mDMAPipes = 0;
     mFeatures = 0;
-    mMDPUpscale = 0;
-    mMDPDownscale = 0;
+    mMDPUpscale = 1;
+    mMDPDownscale = 1;
     mMacroTileEnabled = false;
     mLowBw = 0;
     mHighBw = 0;