AudioFlinger: Account for frames dropped in suspend mode

These frames must be added to the kernel position in timestamps.

Bug: 30025777
Change-Id: I30c14503c9467059c3782e5c96c01ae1cf3709f6
diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index 2fd7eeb..6aad4bf 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -721,6 +721,7 @@
 
     int64_t                         mBytesWritten;
     int64_t                         mFramesWritten; // not reset on standby
+    int64_t                         mSuspendedFrames; // not reset on standby
 private:
     // mMasterMute is in both PlaybackThread and in AudioFlinger.  When a
     // PlaybackThread needs to find out if master-muted, it checks it's local