hwc: Source Split layers always if indicated by driver

Source Split layers always if the driver indicates so by setting
the src_split_always in the capabilities sysfs node.
This is applicable to layers whose width > mixer's width, since
MDP clk rate is dependent on max(mixer_width, layer_width).

This feature can be enabled if the panel height is more than a
certain empirically derived value. Splitting always in those
cases can help with a lower voltage.

Change-Id: If9b33f11ca4132eb77416c26819f7473c65d3b08
diff --git a/libqdutils/mdp_version.h b/libqdutils/mdp_version.h
index e862d2d..8bb9c39 100644
--- a/libqdutils/mdp_version.h
+++ b/libqdutils/mdp_version.h
@@ -140,6 +140,7 @@
     unsigned long getLowBw() { return mLowBw; }
     unsigned long getHighBw() { return mHighBw; }
     bool isSrcSplit() const;
+    bool isSrcSplitAlways() const;
     bool isRGBScalarSupported() const;
     bool is8x26();
     bool is8x74v2();
@@ -170,6 +171,8 @@
     unsigned long mLowBw; //kbps
     unsigned long mHighBw; //kbps
     bool mSourceSplit;
+    //Additional property on top of source split
+    bool mSourceSplitAlways;
     bool mRGBHasNoScalar;
 };
 }; //namespace qdutils