power: Fix VNDK Compilation Errors

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

Change-Id: I4c72a28ffa141ecadcfe47cc7c1f62f2a0c8576e

power-845.c

@@ -37,6 +37,8 @@
 #include <fcntl.h>
 #include <dlfcn.h>
 #include <stdlib.h>
+#include <pthread.h>
+#include <unistd.h>
 
 #define LOG_TAG "QTI PowerHAL"
 #include <utils/Log.h>

power.c

@@ -36,6 +36,7 @@
 #include <fcntl.h>
 #include <dlfcn.h>
 #include <stdlib.h>
+#include <unistd.h>
 
 #define LOG_TAG "QTI PowerHAL"
 #include <utils/Log.h>

powerhintparser.c

@@ -32,6 +32,7 @@
 #include <cutils/properties.h>
 #include <libxml/parser.h>
 #include <libxml/tree.h>
+#include <unistd.h>
 #include "powerhintparser.h"
 #define LOG_TAG "QTI PowerHAL"
 

utils.c

@@ -33,6 +33,7 @@
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 
 #include "utils.h"
 #include "list.h"