Fix warning for Android NDK compiler: "function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]"

https://stackoverflow.com/questions/42125/warning-error-function-declaration-isnt-a-prototype
In C int foo() and int foo(void) are different functions. int foo() accepts an arbitrary number of arguments, while int foo(void) accepts 0 arguments. In C++ they mean the same thing.

Xcode-iOS/Demos/src/keyboard.c

@@ -196,7 +196,7 @@ loadFont(void)
 }
 
 void
-draw()
+draw(void)
 {
     SDL_SetRenderDrawColor(renderer, bg_color.r, bg_color.g, bg_color.b, bg_color.a);
     SDL_RenderClear(renderer);