vout_ios2: partially revert commit 83228de5 due broken scaleFactor (refs #11745)

Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>
(cherry picked from commit 3870474bc915b9bfdf8d4df6e4ade760f0f3a7a7)

modules/video_output/ios2.m

@@ -307,6 +307,10 @@ static int Control(vout_display_t *vd, int query, va_list ap)
                 sys->place = place;
             }
 
+            // x / y are top left corner, but we need the lower left one
+            if (query != VOUT_DISPLAY_CHANGE_DISPLAY_SIZE)
+                glViewport(place.x, cfg_tmp.display.height - (place.y + place.height), place.width, place.height);
+
             [autoreleasePool release];
             return VLC_SUCCESS;
         }