Tinyalsa: add pcm_delay()

ALSA supports reporting of pcm_delay, make that availble to the users of
tinyalsa too

Change-Id: Ic460f5c55137d263fdf7b142503d3bd52c4b7ebd
Signed-off-by: Hardik T Shah <hardik.t.shah@intel.com>
Signed-off-by: Apelete Seketeli <apeletex.seketeli@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/pcm.c b/pcm.c
index 5381a89..90c9dad 100644
--- a/pcm.c
+++ b/pcm.c
@@ -170,6 +170,7 @@
     struct snd_pcm_sync_ptr *sync_ptr;
     void *mmap_buffer;
     unsigned int noirq_frames_per_msec;
+    long pcm_delay;
 };
 
 unsigned int pcm_get_buffer_size(struct pcm *pcm)
@@ -1046,3 +1047,11 @@
 
     return pcm_mmap_transfer(pcm, data, count);
 }
+
+long pcm_get_delay(struct pcm *pcm)
+{
+    if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_DELAY, &pcm->pcm_delay) < 0)
+        return -1;
+
+    return pcm->pcm_delay;
+}