Include unistd.h in OpenGLES2App.cpp as usleep is used in code

Signed-off-by: Andrei Gherzan <andrei.gherzan@windriver.com>
Upstream-status: Pending

Index: git/LayerManagerExamples/EGLX11MockNavigation/src/OpenGLES2App.cpp
===================================================================
--- git.orig/LayerManagerExamples/EGLX11MockNavigation/src/OpenGLES2App.cpp	2012-05-16 13:52:30.114057234 +0300
+++ git/LayerManagerExamples/EGLX11MockNavigation/src/OpenGLES2App.cpp	2012-05-16 13:52:46.674056640 +0300
@@ -28,6 +28,8 @@
 #include <math.h>
 #include <sys/time.h>
 
+#include <unistd.h>
+
 #define RUNTIME_IN_MS() (GetTickCount() - startTimeInMS)
 
 // Max width and height of the window