dr_mp3: Remove some unused compile time options.

Public issue #173

dr_mp3.h

@@ -1,6 +1,6 @@
 /*
 MP3 audio decoder. Choice of public domain or MIT-0. See license statements at the end of this file.
-dr_mp3 - v0.6.24 - 2020-12-07
+dr_mp3 - v0.6.25 - TBD
 
 David Reid - [email protected]
 
@@ -95,7 +95,7 @@ extern "C" {
 
 #define DRMP3_VERSION_MAJOR     0
 #define DRMP3_VERSION_MINOR     6
-#define DRMP3_VERSION_REVISION  23
+#define DRMP3_VERSION_REVISION  25
 #define DRMP3_VERSION_STRING    DRMP3_XSTRINGIFY(DRMP3_VERSION_MAJOR) "." DRMP3_XSTRINGIFY(DRMP3_VERSION_MINOR) "." DRMP3_XSTRINGIFY(DRMP3_VERSION_REVISION)
 
 #include <stddef.h> /* For size_t. */
@@ -281,14 +281,6 @@ DRMP3_API void drmp3dec_f32_to_s16(const float *in, drmp3_int16 *out, size_t num
 Main API (Pull API)
 ===================
 */
-#ifndef DRMP3_DEFAULT_CHANNELS
-#define DRMP3_DEFAULT_CHANNELS      2
-#endif
-#ifndef DRMP3_DEFAULT_SAMPLE_RATE
-#define DRMP3_DEFAULT_SAMPLE_RATE   44100
-#endif
-
-
 typedef enum
 {
     drmp3_seek_origin_start,
@@ -4458,6 +4450,9 @@ counts rather than sample counts.
 /*
 REVISION HISTORY
 ================
+v0.6.25 - TBD
+  - Remove DRMP3_DEFAULT_CHANNELS and DRMP3_DEFAULT_SAMPLE_RATE which are leftovers from some removed APIs.
+
 v0.6.24 - 2020-12-07
   - Fix a typo in version date for 0.6.23.