Pull sound fixes from Takashi Iwai:
 "This update contains mostly only fixes for Realtek HD-audio codec
  driver in addition to a long-standing sysfs warning bug fix for
  USB-audio.

  One significant fix for Realtek codecs is the update of EAPD init
  codes.  This avoids invalid COEF setups for some codec models and may
  fix "lost sound" in some cases.

  The rest are a bit high volume but only new quirks and ALC668-specific
  COEF tables"

* tag 'sound-3.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda/realtek - Restore default value for ALC668
  ALSA: usb-audio: Fix device_del() sysfs warnings at disconnect
  ALSA: hda - fix mute led problem for three HP laptops
  ALSA: hda/realtek - Update Initial AMP for EAPD control
  ALSA: hda - change three SSID quirks to one pin quirk
  ALSA: hda - Set GPIO 4 low for a few HP machines
  ALSA: hda - Add ultra dock support for Thinkpad X240.