Fix the RS frame timeout.
Previous a slow app would block from receiving new
commands until the timer expired.  This change will
expire the timer immediatly.

Change-Id: I42b949d21f98ee0f1d3156763cd723c3e9cabb67
diff --git a/libs/rs/rsSignal.h b/libs/rs/rsSignal.h
index 2e760f1..fc31883 100644
--- a/libs/rs/rsSignal.h
+++ b/libs/rs/rsSignal.h
@@ -31,7 +31,10 @@
     bool init();
 
     void set();
-    void wait();
+
+    // returns true if the signal occured
+    // false for timeout
+    bool wait(uint64_t timeout = 0);
 
 protected:
     bool mSet;