os2: can build with libsamplerate support if wanted to.
diff --git a/include/SDL_config_os2.h b/include/SDL_config_os2.h
index 8c7a069..1c9b187 100644
--- a/include/SDL_config_os2.h
+++ b/include/SDL_config_os2.h
@@ -53,10 +53,11 @@
/* Enable assembly routines */
#define SDL_ASSEMBLY_ROUTINES 1
-/* #undef HAVE_LIBSAMPLERATE_H */
+/* use libsamplerate for audio rate conversion. */
+/*#define HAVE_LIBSAMPLERATE_H 1 */
/* Enable dynamic libsamplerate support */
-/* #undef SDL_LIBSAMPLERATE_DYNAMIC */
+#define SDL_LIBSAMPLERATE_DYNAMIC "SAMPRATE.DLL"
#define HAVE_LIBC 1