audio HAL: do not stop capture on overrun

Set stop threshold so that PCM driver does
not stop capture in case of overrun.

Bug: 19209668.
Change-Id: I89b2cae617d73c17c859e9f1c192b4f3db79cc18
diff --git a/hal/audio_hw.c b/hal/audio_hw.c
index 6757802..1f9b63f 100644
--- a/hal/audio_hw.c
+++ b/hal/audio_hw.c
@@ -113,6 +113,8 @@
     .channels = 2,
     .period_count = AUDIO_CAPTURE_PERIOD_COUNT,
     .format = PCM_FORMAT_S16_LE,
+    .stop_threshold = INT_MAX,
+    .avail_min = 0,
 };
 
 #define AFE_PROXY_CHANNEL_COUNT 2