DirectFB: fix DirectFB_SetTextureScaleMode() declaration

Fixes:

  src/video/directfb/SDL_DirectFB_render.c: In function ‘DirectFB_CreateRenderer’:
  src/video/directfb/SDL_DirectFB_render.c:1153:35: error: assignment to ‘void (*)(SDL_Renderer *, SDL_Texture *, SDL_ScaleMode)’ from incompatible pointer type ‘void (*)(void)’ [-Wincompatible-pointer-types]
   1153 |     renderer->SetTextureScaleMode = DirectFB_SetTextureScaleMode;
        |                                   ^

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
---
Notes:
  - declaration was just recently changed by commit 'Fix warning for Android
    NDK compiler: "function declaration without a prototype is deprecated in
    all versions of C [-Wstrict-prototypes]"', see
    https://github.com/libsdl-org/SDL/commit/ccade505879333267c8d6d38cb9c0535596f4648

src/video/directfb/SDL_DirectFB_render.c

@@ -561,7 +561,7 @@ static void DirectFB_UnlockTexture(SDL_Renderer * renderer, SDL_Texture * textur
     }
 }
 
-static void DirectFB_SetTextureScaleMode(void)
+static void DirectFB_SetTextureScaleMode(SDL_Renderer * renderer, SDL_Texture * texture, SDL_ScaleMode scaleMode)
 {
 }