[ALSA] emu10k1 - Fix missing declarations

Modules: EMU10K1/EMU10K2 driver

sound/pci/emu10k1/emufx.c: In function 'snd_emu10k1_efx_alloc_pm_buffer':
sound/pci/emu10k1/emufx.c:2402: error: implicit declaration of function 'vmalloc'
sound/pci/emu10k1/emufx.c:2402: warning: assignment makes pointer from integer without a cast
sound/pci/emu10k1/emufx.c: In function 'snd_emu10k1_efx_free_pm_buffer':
sound/pci/emu10k1/emufx.c:2413: error: implicit declaration of function 'vfree'

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