Allow the WavPack’s output buffer to be optionally allocated in IRAM

The decoder does use `memset` on the buffer, but according to Espressif that should be fine.

See-Also: https://docs.espressif.com/projects/esp-idf/en/stable/esp32/api-reference/system/mem_alloc.html#bit-accessible-memory
See-Also: https://esp32.com/viewtopic.php?t=1730#p8056

src/codecs/wavpack.cpp

@@ -45,7 +45,7 @@ WavPackDecoder::WavPackDecoder() : input_(), buf_() {
   buf_ = static_cast<int32_t*>(
       heap_caps_malloc(
           kBufSize * sizeof(int32_t),
-          MALLOC_CAP_INTERNAL | MALLOC_CAP_CACHE_ALIGNED
+          MALLOC_CAP_INTERNAL | MALLOC_CAP_32BIT
   ));
 }