ALSA: emu10k1 - Fix page allocation with GFP_DMA

Added the missing GFP_ATOMIC to page_alloc when called with GFP_DMA.
GFP_KERNEL often results in stalls for ZONE_DMA, so GFP_ATOMIC is more
prgmatic.

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