hwcomposer: In Mdss,secure content policy applies to layer buffer

In Mdss, mSecureMode is never set, instead the secure content flag
has been set/unset on each layer buffer.

Change-Id: I3283533c11206e189ce70dbc84776b2cff3a909d
diff --git a/libhwcomposer/hwc_utils.cpp b/libhwcomposer/hwc_utils.cpp
index 9cc5c24..7a3adbb 100644
--- a/libhwcomposer/hwc_utils.cpp
+++ b/libhwcomposer/hwc_utils.cpp
@@ -226,6 +226,12 @@
     return false;
 }
 
+bool isSecureModePolicy(int mdpVersion) {
+    if (mdpVersion < qdutils::MDSS_V5)
+        return true;
+    else
+        return false;
+}
 
 //Crops source buffer against destination and FB boundaries
 void calculate_crop_rects(hwc_rect_t& crop, hwc_rect_t& dst,