[ion/display] Factorize the dummy waitForVBlank

ion/src/blackbox/display.cpp

@@ -29,9 +29,6 @@ void pullRect(KDRect r, KDColor * pixels) {
   }
 }
 
-void waitForVBlank() {
-}
-
 }
 }
 

ion/src/emscripten/display.cpp

@@ -27,9 +27,6 @@ void pullRect(KDRect r, KDColor * pixels) {
   sFrameBuffer.pullRect(r, pixels);
 }
 
-void waitForVBlank() {
-}
-
 }
 }
 

ion/src/shared/dummy/display.cpp

@@ -2,3 +2,6 @@
 
 void Ion::Display::POSTPushBlackWhite() {
 }
+
+void Ion::Display::waitForVBlank() {
+}

ion/src/simulator/init.cpp

@@ -71,9 +71,6 @@ void Ion::Display::pullRect(KDRect r, KDColor * pixels) {
   sFrameBuffer->pullRect(r, pixels);
 }
 
-void Ion::Display::waitForVBlank() {
-}
-
 Ion::Keyboard::State Ion::Keyboard::scan() {
   Ion::Keyboard::State result = 0;
   for (int i = 0; i < Ion::Keyboard::NumberOfKeys; i++) {