libhwcomposer: Add support for 4 layer MDP Comp

This change extends MDP composition to support
upto 4 layers by making border fill as base pipe and
using all MDP h/w pipes in overlay mode.

Conflicts:

	libhwcomposer/hwc.cpp
	libhwcomposer/hwc_utils.cpp
	libhwcomposer/hwc_utils.h

Bug: 7626586
Change-Id: I01a0e53ddfbcf3ed46734f6f3bb0ef7d912ceac6
Signed-off-by: Jeykumar Sankaran <jsanka@codeaurora.org>
Signed-off-by: Iliyan Malchev <malchev@google.com>
diff --git a/libhwcomposer/hwc_video.cpp b/libhwcomposer/hwc_video.cpp
index 5fba951..48cb165 100644
--- a/libhwcomposer/hwc_video.cpp
+++ b/libhwcomposer/hwc_video.cpp
@@ -40,6 +40,11 @@
        return false;
     }
 
+    if(isSecuring(ctx)) {
+       ALOGD_IF(VIDEO_DEBUG,"%s: MDP Secure is active", __FUNCTION__);
+       return false;
+    }
+
     if(yuvIndex == -1 || ctx->listStats[dpy].yuvCount != 1) {
         return false;
     }
@@ -106,13 +111,9 @@
         isFgFlag = ovutils::IS_FG_SET;
     }
 
-    //TODO change to 1 always when primary FB uses overlay.
-    const ovutils::eZorder zorder = (dpy == HWC_DISPLAY_PRIMARY) ?
-            ovutils::ZORDER_0 : ovutils::ZORDER_1;
-
     ovutils::PipeArgs parg(mdpFlags,
             info,
-            zorder,
+            ovutils::ZORDER_1,
             isFgFlag,
             ovutils::ROT_FLAG_DISABLED);