ALSA: emu10k1: Emu10k2 32 bit DMA mode

ALSA: emu10k1: Emu10k2 32 bit DMA mode

Looks like audigy emu10k2 (probably emu10k1 - sb live too) support two
modes for DMA. Second mode is useful for 64 bit os with more then 2 GB
of ram (fixes problems with big soundfont loading)

1) 32MB from 2 GB address space using 8192 pages (used now as default)
2) 16MB from 4 GB address space using 4096 pages

Mode is set using HCFG_EXPANDED_MEM flag in HCFG register.
Also format of emu10k2 page table is then different.

Signed-off-by: Peter Zubaj <[email protected]>
Tested-by: Takashi Iwai <[email protected]>
Cc: <[email protected]>
Signed-off-by: Takashi Iwai <[email protected]>