ALSA: pcm: call delay_blk op from DELAY ioctl

Call the delay_blk() pcm op from the
SNDRV_PCM_IOCTL_DELAY ioctl.  This will update the
runtime->delay field with the current DSP path
delay before it is used to return the total delay.

Change-Id: I485139666a639566782a93b566b30899f2f5e791
Signed-off-by: Kenneth Westfield <kwestfie@codeaurora.org>