[ALSA] intel8x0 - Use pci_iomap

Use pci_iomap and ioread*/iowrite*() functions for accessing
hardwares.  pci_iomap is suitable for hardwares like ICH and
compatible that have both PIO and MMIO.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>