feat(audio): add USB Audio Host (UAC 1.0) support

Add TinyUSB Host Audio class driver supporting UAC 1.0 devices.

Features:
- Support multiple Audio Streaming (AS) interfaces with independent format storage
- Support both IN (Microphone) and OUT (Speaker) endpoints
- Per-AS interface format info: channels, sample rate, bit resolution
- Support Feature Unit volume control
- Support sampling frequency get/set
- Add host/audio_host example for STM32F407 discovery board
- Support mono-to-stereo conversion for loopback

Changes:
- Add src/class/audio/audio_host.c and audio_host.h
- Register AUDIO driver in usbh.c
- Add CFG_TUH_AUDIO macro in tusb_option.h
- Add host/audio_host example with CMake and Makefile build support

Tested with Jabra USB headset (stereo speaker + mono microphone) on STM32F407 disco.

1 files changed, 12 insertions, 0 deletions

diff --git a/src/host/usbh.c b/src/host/usbh.c
index e307bb5e5..6e16c0b72 100644
--- a/src/host/usbh.c
+++ b/src/host/usbh.c
@@ -258,6 +258,18 @@ static usbh_class_driver_t const usbh_class_drivers[] = {
   },
   #endif
 
+  #if CFG_TUH_AUDIO
+  {
+      .name       = DRIVER_NAME("AUDIO"),
+      .init       = audioh_init,
+      .deinit     = audioh_deinit,
+      .open       = audioh_open,
+      .set_config = audioh_set_config,
+      .xfer_cb    = audioh_xfer_cb,
+      .close      = audioh_close
+  },
+  #endif
+
   #if CFG_TUH_HID
   {
       .name       = DRIVER_NAME("HID"),