Bluetooth: Add DFU driver for Atheros Bluetooth chipset AR3011

Signed-off-by: Vikram Kandukuri <vikram.kandukuri@atheros.com>
Signed-off-by: Alicke Xu <sxu@atheros.com>
Reviewed-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>