ALSA: hda - Cirrus: Correctly clear line_out_pins when moving to speaker

If this array is not cleared, the jack related code later might
fail to create "Internal Speaker Phantom Jack" on Dell Inspiron 3420 and
Dell Vostro 2420.

BugLink: https://bugs.launchpad.net/bugs/1076840


Cc: stable@vger.kernel.org (3.6+)
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>