MT#40962 remove 2 ms sleep exemption

Go to sleep even if the sleep time is less than 2 ms. This makes the
math a lot easier and shouldn't have a noticeable impact as this is
a somewhat unnecessary attempt at optimization.

Change-Id: Ibd97c216e529b4e0b2110f81200b649db6ff2764

core/AmMediaProcessor.cpp

@@ -249,7 +249,7 @@ void AmMediaProcessorThread::run()
 
       uint64_t diff = next_tick - now;
 
-      if(diff > 2000) // 2 ms
+      if(diff)
         usleep(diff);
     }