bt: Include DMA reserved pool when allocating internal-only memory

Fix for root cause of https://github.com/espressif/esp-idf/issues/3592

components/bt/bt.c

@@ -753,7 +753,7 @@ static int IRAM_ATTR cause_sw_intr_to_core_wrapper(int core_id, int intr_no)
 
 static void *malloc_internal_wrapper(size_t size)
 {
-    return heap_caps_malloc(size, MALLOC_CAP_DEFAULT|MALLOC_CAP_INTERNAL);
+    return heap_caps_malloc(size, MALLOC_CAP_8BIT|MALLOC_CAP_DMA|MALLOC_CAP_INTERNAL);
 }
 
 static int32_t IRAM_ATTR read_mac_wrapper(uint8_t mac[6])