[ALSA] hda-codec - Don't return error at initialization of modem codec

Some modem codec seem to fail in the initialization, and this
stopped loading of the whole module although the audio is OK.
Since it's usually a non-fatal issue, the driver tries to proceed
to initialize now.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>