hqd: Restrict decimation when layer format is macro-tile

When layer format is macro-tile, decimation cannot be supported.
Add necessary checks to bail out for such use-case.

Change-Id: I711f07a2963a76280a08887d04770cd418d8bd1e
diff --git a/libhwcomposer/hwc_mdpcomp.h b/libhwcomposer/hwc_mdpcomp.h
index 94199e3..22b8baf 100644
--- a/libhwcomposer/hwc_mdpcomp.h
+++ b/libhwcomposer/hwc_mdpcomp.h
@@ -226,6 +226,7 @@
     /* Handles the timeout event from kernel, if the value is set to true */
     static bool sHandleTimeout;
     static int sMaxPipesPerMixer;
+    static bool sSrcSplitEnabled;
     static IdleInvalidator *idleInvalidator;
     struct FrameInfo mCurrentFrame;
     struct LayerCache mCachedFrame;