ALSA: hda/realtek - Allow NULL bus->pci

Realtek codec driver contains some codes referring to the PCI
subdevice IDs, but most of them are optional, typically for checking
the codec name variants.  Add NULL checks appropriately so that it can
work without PCI assignment.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
1 file changed