added hint for joysticks to stablize sixaxis & dualshock controllers (#5007)

test/testgamecontroller.c

@@ -530,6 +530,7 @@ main(int argc, char *argv[])
     SDL_SetHint(SDL_HINT_JOYSTICK_HIDAPI_PS4_RUMBLE, "1");
     SDL_SetHint(SDL_HINT_JOYSTICK_HIDAPI_PS5_RUMBLE, "1");
     SDL_SetHint(SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS, "1");
+    SDL_SetHint(SDL_HINT_LINUX_JOYSTICK_DEADZONES, "1");
 
     /* Enable standard application logging */
     SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);