Without this terminating entry, the pin matching would continue
across random memory until a zero or a non-matching entry was found.

The result being that in some cases, the pin quirk would not be
applied correctly.

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