Fix VNDK Compilation Errors

VNDK restrictions doesn't includes standard headers by
default, add them explicitly.

Change-Id: Icafac6f07fcdf58fccaabde8d472509090fb3e6f
diff --git a/post_proc/effect_api.c b/post_proc/effect_api.c
index b01acc5..3098850 100644
--- a/post_proc/effect_api.c
+++ b/post_proc/effect_api.c
@@ -62,6 +62,8 @@
 #include <sound/devdep_params.h>
 #include <linux/msm_audio.h>
 #include <errno.h>
+#include <unistd.h>
+#include <stdio.h>
 #include "effect_api.h"
 
 #ifdef DTS_EAGLE