Use 3 ms buffers for low latency path

Change-Id: Icf113e2e863a79cb3d870fac5781539702cdbfa8
diff --git a/audio/audio_hw.c b/audio/audio_hw.c
index b841c57..f2fda76 100644
--- a/audio/audio_hw.c
+++ b/audio/audio_hw.c
@@ -127,7 +127,7 @@
 /* #define to use mmap no-irq mode for playback, #undef for non-mmap irq mode */
 #undef PLAYBACK_MMAP        // was #define
 /* short period (aka low latency) in milliseconds */
-#define SHORT_PERIOD_MS 4   // was 22
+#define SHORT_PERIOD_MS 3   // was 22
 /* deep buffer short period (screen on) in milliseconds */
 #define DEEP_BUFFER_SHORT_PERIOD_MS 22
 /* deep buffer long period (screen off) in milliseconds */