tga files for Freezers/Kernal

[soenkesmiletzki]

Request to use tga files for "Freezers" and "Kernal" for the display.

Idea: if a .tga files available it will be loaded, else the default file will be loaded.

[frntc]

I also had that in mind after your comment on forum64. I'll put that on the list for the next update ;-)