Added mixer and sound (c side)

src/sound.c

@@ -0,0 +1,15 @@
+#include <stdint.h>
+#include "sound.h"
+#include "lib/dmt/dmt.h"
+
+int sound_init(sound_t *self, int samples) {
+  self->sampleCount = samples;
+  self->samples = (int16_t*)dmt_malloc(samples * sizeof(int16_t));
+  return 0;
+}
+
+
+void sound_deinit(sound_t *self) {
+  dmt_free(self->samples);
+}
+