Work around the lack of clock() on PS Vita

src/test/SDL_test_harness.c

@@ -349,7 +349,7 @@ static void SDLTest_LogTestSuiteSummary(SDLTest_TestSuiteReference *testSuites)
 /* Gets a timer value in seconds */
 static float GetClock()
 {
-    float currentClock = clock() / (float) CLOCKS_PER_SEC;
+    float currentClock = SDL_GetPerformanceCounter() / (float) SDL_GetPerformanceFrequency();
     return currentClock;
 }
 

src/test/SDL_test_random.c

@@ -70,7 +70,7 @@ void SDLTest_RandomInitTime(SDLTest_RandomContext * rndContext)
 
   srand((unsigned int)time(NULL));
   a=rand();
-  srand((unsigned int)clock());
+  srand((unsigned int)SDL_GetPerformanceCounter());
   b=rand();
   SDLTest_RandomInit(rndContext, a, b);
 }