hwc: HDMI-WFD synchronization changes

The changes from WFD to issue a binder call to notify about
WFD session tear down is in place. Hence the changes done via
change id :I9514cb5bc7ff81de0b5dd4cdf66d8286a64ba094 is
partially reverted.

Change-Id: Ie567749876825cf6dea7bd4c7ff14cf13d10043b
diff --git a/libhwcomposer/hwc_uevents.cpp b/libhwcomposer/hwc_uevents.cpp
index a552b04..5399e03 100644
--- a/libhwcomposer/hwc_uevents.cpp
+++ b/libhwcomposer/hwc_uevents.cpp
@@ -254,23 +254,14 @@
                         }
                     }
 
-                    /*TODO: Uncomment the below chunk and remove usleep
-                      once wfd module issues binder call on teardown */
-
-                    /*ctx->mWfdSyncLock.lock();
+                    ctx->mWfdSyncLock.lock();
                     ALOGD_IF(HWC_WFDDISPSYNC_LOG,
                              "%s: Waiting for wfd-teardown to be signalled",
                              __FUNCTION__);
                     ctx->mWfdSyncLock.wait();
                     ALOGD_IF(HWC_WFDDISPSYNC_LOG,
                              "%s: Teardown signalled",__FUNCTION__);
-                    ctx->mWfdSyncLock.unlock();*/
-
-                    /* For now, Wait for few frames for SF to tear down
-                     * the WFD session.
-                     */
-                    usleep(ctx->dpyAttr[HWC_DISPLAY_PRIMARY].vsync_period
-                           * 2 / 1000);
+                    ctx->mWfdSyncLock.unlock();
                 }
                 ctx->mExtDisplay->configure();
             } else {