[glibc] LoongArch: Add vdso support for gettimeofday.

[Yinyu Cai <caiyinyu@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=3e838436370cd97ffaacec5cb663aa03f97a16db

commit 3e838436370cd97ffaacec5cb663aa03f97a16db
Author: caiyinyu <caiyinyu@loongson.cn>
Date:   Thu Jul 14 08:54:04 2022 +0800

    LoongArch: Add vdso support for gettimeofday.

Diff:
---
 sysdeps/unix/sysv/linux/loongarch/gettimeofday.c | 22 ++++++++++++++++++++++
 sysdeps/unix/sysv/linux/loongarch/sysdep.h       |  1 +
 2 files changed, 23 insertions(+)

diff --git a/sysdeps/unix/sysv/linux/loongarch/gettimeofday.c b/sysdeps/unix/sysv/linux/loongarch/gettimeofday.c
new file mode 100644
index 0000000000..ee35a08650
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/loongarch/gettimeofday.c
@@ -0,0 +1,22 @@
+/* gettimeofday -- Get the current time of day.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+
+#define USE_IFUNC_GETTIMEOFDAY
+#include <sysdeps/unix/sysv/linux/gettimeofday.c>
diff --git a/sysdeps/unix/sysv/linux/loongarch/sysdep.h b/sysdeps/unix/sysv/linux/loongarch/sysdep.h
index e4c8fc2936..8a398adb70 100644
--- a/sysdeps/unix/sysv/linux/loongarch/sysdep.h
+++ b/sysdeps/unix/sysv/linux/loongarch/sysdep.h
@@ -116,6 +116,7 @@
 /* List of system calls which are supported as vsyscalls.  */
 #define HAVE_CLOCK_GETRES64_VSYSCALL "__vdso_clock_getres"
 #define HAVE_CLOCK_GETTIME64_VSYSCALL "__vdso_clock_gettime"
+#define HAVE_GETTIMEOFDAY_VSYSCALL "__vdso_gettimeofday"
 #define HAVE_GETCPU_VSYSCALL "__vdso_getcpu"
 
 #define HAVE_CLONE3_WRAPPER 1