ALSA: hda/ca0132 - make pci_iounmap() call conditional

When building without CONFIG_PCI, we can (depending on the architecture)
get a link failure:

ERROR: "pci_iounmap" [sound/pci/hda/snd-hda-codec-ca0132.ko] undefined!

Adding a compile-time check for PCI gets it to work correctly on
32-bit ARM.

Fixes: d99501b8 ("ALSA: hda/ca0132 - Call pci_iounmap() instead of iounmap()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>