posix: Move gettimeofday declaration to <sys/time.h>

According to POSIX, that's the header which defines this function.
Similarly, nothing in POSIX indicates that <time.h> should have
access to struct timeval, so it's removed (it's made accessible
to <sys/time.h> via <sys/_timeval.h> introduced earlier).

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>

include/posix/sys/time.h

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2019 Linaro Limited
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_INCLUDE_POSIX_SYS_TIME_H_
+#define ZEPHYR_INCLUDE_POSIX_SYS_TIME_H_
+
+#include <sys/_timeval.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int gettimeofday(struct timeval *tv, const void *tz);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* ZEPHYR_INCLUDE_POSIX_SYS_TIME_H_ */

include/posix/time.h

@@ -34,11 +34,6 @@ struct itimerspec {
 };
 #endif
 
-struct timeval {
-	signed int  tv_sec;
-	signed int  tv_usec;
-};
-
 #include <kernel.h>
 #include <errno.h>
 #include "posix_types.h"
@@ -72,8 +67,6 @@ int timer_gettime(timer_t timerid, struct itimerspec *its);
 int timer_settime(timer_t timerid, int flags, const struct itimerspec *value,
 		  struct itimerspec *ovalue);
 
-int gettimeofday(struct timeval *tv, const void *tz);
-
 #ifdef __cplusplus
 }
 #endif

lib/posix/clock.c

@@ -6,6 +6,7 @@
 #include <kernel.h>
 #include <errno.h>
 #include <posix/time.h>
+#include <posix/sys/time.h>
 
 /*
  * `k_uptime_get` returns a timestamp based on an always increasing

tests/posix/common/src/clock.c

@@ -5,6 +5,7 @@
  */
 #include <ztest.h>
 #include <posix/time.h>
+#include <posix/sys/time.h>
 #include <posix/unistd.h>
 
 #define SLEEP_SECONDS 1