Recently the check for non-PCM stream state was added to the generic
HDMI driver code.  But this check should be done rather to each pin
instead of each converter.  Otherwise when a different converter is
assigned at the next open, the audio infoframe can be inconsistent
with the setup using the previous converter.

For fixing this issue, this patch moves the state of the current
non-PCM status from per_cvt to per_pin.  (In addition an unused
argument cvt_nid is stripped from hdmi_setup_channel_mapping())
Signed-off-by: Takashi Iwai <tiwai@suse.de>