[ALSA] intel8x0: do not use zero value from PICB register

It seems that the zero value from the PICB (position in current buffer)
register is not reliable. Use jiffies to correct returned value
from the ring buffer pointer callback.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

diff --cc sound/pci/intel8x0.c
Simple merge