hal: Include pthread.h

Doesn't compile without it.

Change-Id: Ia75404ee1fc735df58fa6f9922063fcf2cc2022d
diff --git a/hal/audio_extn/audio_extn.c b/hal/audio_extn/audio_extn.c
index b7f9f0d..d93bd70 100755
--- a/hal/audio_extn/audio_extn.c
+++ b/hal/audio_extn/audio_extn.c
@@ -45,6 +45,7 @@
 #include <fcntl.h>
 #include <cutils/properties.h>
 #include <log/log.h>
+#include <pthread.h>
 #include <unistd.h>
 #include <sched.h>
 
diff --git a/hal/audio_extn/gef.c b/hal/audio_extn/gef.c
index 69b1e41..dc70717 100644
--- a/hal/audio_extn/gef.c
+++ b/hal/audio_extn/gef.c
@@ -39,6 +39,7 @@
 #include "audio_hw.h"
 #include "platform.h"
 #include "platform_api.h"
+#include <pthread.h>
 #include <sys/stat.h>
 #include <stdlib.h>
 #include <dlfcn.h>
diff --git a/hal/audio_hw_extn_api.c b/hal/audio_hw_extn_api.c
index 4fece7e..6d8901d 100644
--- a/hal/audio_hw_extn_api.c
+++ b/hal/audio_hw_extn_api.c
@@ -42,6 +42,8 @@
 #include "audio_extn.h"
 #include "audio_hw_extn_api.h"
 
+#include <pthread.h>
+
 #ifdef DYNAMIC_LOG_ENABLED
 #include <log_xml_parser.h>
 #define LOG_MASK HAL_MOD_FILE_AUDIO_HW_EXTN_API
diff --git a/hal/platform_info.c b/hal/platform_info.c
index e55b91d..9cfd760 100755
--- a/hal/platform_info.c
+++ b/hal/platform_info.c
@@ -41,6 +41,7 @@
 #include "platform_api.h"
 #include "audio_extn.h"
 #include <platform.h>
+#include <pthread.h>
 #include <math.h>
 #ifdef LINUX_ENABLED
 #include <float.h>