Delete Adafruit's DCD, add stubs for missing DCD functions, use ESP32 core DCD

src/dcd_stubs.c

@@ -0,0 +1,31 @@
+/*
+ * Stub DCD functions required by Adafruit TinyUSB Library's usbd.c
+ * but not provided by ESP32 Arduino core's older libarduino_tinyusb.a.
+ * These are for ISO transfers / SOF interrupt only -- MIDI doesn't use them.
+ */
+#include "tusb.h"
+
+//--------------------------------------------------------------------+
+// SOF (Start of Frame)
+//--------------------------------------------------------------------+
+void dcd_sof_enable(uint8_t rhport, bool enabled) {
+  (void)rhport;
+  (void)enabled;
+}
+
+//--------------------------------------------------------------------+
+// ISO (Isochronous)
+//--------------------------------------------------------------------+
+bool dcd_edpt_iso_alloc(uint8_t rhport, uint8_t dir, uint8_t ep_addr, uint16_t packet_size) {
+  (void)rhport;
+  (void)dir;
+  (void)ep_addr;
+  (void)packet_size;
+  return true;
+}
+
+bool dcd_edpt_iso_activate(uint8_t rhport, tusb_desc_endpoint_t const *p_endpoint_desc) {
+  (void)rhport;
+  (void)p_endpoint_desc;
+  return true;
+}