Ensure the resampler is allocated in internal ram

It's quite small!

lib/speexdsp/libspeexdsp/config.h

@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include "esp_heap_caps.h"
+
 #define FIXED_POINT
 #define EXPORT
 #define STDC_HEADERS
@@ -11,3 +13,19 @@
 
 #define DISABLE_ENCODER
 #define DISABLE_FLOAT_API
+
+#define OVERRIDE_SPEEX_ALLOC
+#define OVERRIDE_SPEEX_REALLOC
+#define OVERRIDE_SPEEX_FREE
+
+static inline void* speex_alloc(int size) {
+  return heap_caps_calloc(size, 1, MALLOC_CAP_INTERNAL | MALLOC_CAP_8BIT);
+}
+
+static inline void* speex_realloc(void* ptr, int size) {
+  return heap_caps_realloc(ptr, size, MALLOC_CAP_INTERNAL | MALLOC_CAP_8BIT);
+}
+
+static inline void speex_free(void* ptr) {
+  heap_caps_free(ptr);
+}