sdl_sound: add hash file

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>

package/sdl_sound/sdl_sound.hash

@@ -0,0 +1,2 @@
+# Locally calculated
+sha256	3999fd0bbb485289a52be14b2f68b571cb84e380cc43387eadf778f64c79e6df	SDL_sound-1.0.3.tar.gz