hwc: Add support for uneven split primary displays

Add support for unevenly split primary displays.
The driver provides info about the split via msm_fb_split sysfs node

For external we assume even split. If driver doesn't specify any split
for primary, we default to even split.

Change-Id: I4d541f41de2d7a5d2b62653fa33cab079a6d5d30
diff --git a/libhwcomposer/hwc_mdpcomp.h b/libhwcomposer/hwc_mdpcomp.h
index 6e04918..908a658 100644
--- a/libhwcomposer/hwc_mdpcomp.h
+++ b/libhwcomposer/hwc_mdpcomp.h
@@ -46,7 +46,8 @@
     /* dumpsys */
     void dump(android::String8& buf);
 
-    static MDPComp* getObject(const int& width, const int dpy);
+    static MDPComp* getObject(const int& width, const int& rightSplit,
+            const int& dpy);
     /* Handler to invoke frame redraw on Idle Timer expiry */
     static void timeout_handler(void *udata);
     /* Initialize MDP comp*/