Pass display arg to blank/unblank

This allows us to blank and unblank displays other than the built-in
display (e.g. HDMI).

Bug: 7240511
Change-Id: I89ea13f9e497be74c3e1231d0c62fb558e93e0f8
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 8f66651..633ca9c 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -92,10 +92,10 @@
     status_t commit();
 
     // release hardware resources and blank screen
-    status_t release() const;
+    status_t release(int disp) const;
 
     // acquire hardware resources and unblank screen
-    status_t acquire() const;
+    status_t acquire(int disp) const;
 
     // create a work list for numLayers layer. sets HWC_GEOMETRY_CHANGED.
     status_t createWorkList(int32_t id, size_t numLayers);