ALSA: usb-audio: clean up includes in clock.c

#include <linux/bitops.h>

#include <linux/init.h>

#include <linux/list.h>

#include <linux/slab.h>

#include <linux/string.h>

#include <linux/usb.h>

#include <linux/moduleparam.h>

#include <linux/mutex.h>

#include <linux/usb/audio.h>

#include <linux/usb/audio-v2.h>

#include <sound/core.h>

#include <sound/info.h>

#include <sound/pcm.h>

#include <sound/pcm_params.h>

#include <sound/initval.h>

#include "usbaudio.h"

#include "card.h"

#include "midi.h"

#include "mixer.h"

#include "proc.h"

#include "quirks.h"

#include "endpoint.h"

#include "helper.h"

#include "debug.h"

#include "pcm.h"

#include "urb.h"

#include "format.h"

#include "clock.h"

static struct uac_clock_source_descriptor *

	snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface,