Add ACCESSORY_SET_AUDIO_MODE control request and ioctl

The control request will be used by the host to enable/disable USB audio
and the ioctl will be used by userspace to read the audio mode

Change-Id: I48082ce473eb6577b0bf613be9ec27f2f5c19384
Signed-off-by: Mike Lockwood <lockwood@google.com>
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>
2 files changed