ALSA: Enable CONFIG_ZONE_DMA for smaller PCI DMA masks

ALSA: Enable CONFIG_ZONE_DMA for smaller PCI DMA masks

commit 80ab8eae70e51d578ebbeb228e0f7a562471b8b7 upstream.

The PCI devices with DMA masks smaller than 32bit should enable
CONFIG_ZONE_DMA.  Since the recent change of page allocator, page
allocations via dma_alloc_coherent() with the limited DMA mask bits
may fail more frequently, ended up with no available buffers, when
CONFIG_ZONE_DMA isn't enabled.  With CONFIG_ZONE_DMA, the system has
much more chance to obtain such pages.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=68221
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>