ALSA: atiixp: Proper endian notations

The DMA address table in atiixp driver is in little-endian, hence we should define it with __le32 properly.

Spotted by sparse, a warning like:
  sound/pci/atiixp.c:393:28: warning: incorrect type in assignment (different base types)

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