[ALSA] Allow shared IRQ for CS5530 device

CS5530 is a PCI device and often shares the IRQ although the SB common
routine tries to allocate it exclusively.  This patch allows shared IRQ
for CS5530.

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