There are references in the code to 256 sources, so I tested it with 256 aplays,
of which the first and last with real data and the rest playing /dev/zero .

Also increase amount of page tables, so the default aplay size works.
Signed-off-by: NMaarten Lankhorst <m.b.lankhorst@gmail.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>