selftests/nolibc: add new gettimeofday test cases

These 2 test cases are added to cover the normal using scenes of
gettimeofday().

They have been used to trigger and fix up such issue with nolibc:

    nolibc-test.c:(.text.gettimeofday+0x54): undefined reference to `__aeabi_ldivmod'

This issue happens while there is no "unsigned int" conversion in the
coming new clock_gettime / clock_gettime64 syscall path of
gettimeofday():

    tv->tv_usec = ts.tv_nsec / 1000;
Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/linux-riscv/280867a8-7601-4a96-9b85-87668e1f1282@t-8ch.de/Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/testing/selftests/nolibc/nolibc-test.c

@@ -539,6 +539,8 @@ static int test_stat_timestamps(void)
  */
 int run_syscall(int min, int max)
 {
+	struct timeval tv;
+	struct timezone tz;
 	struct stat stat_buf;
 	int euid0;
 	int proc;
@@ -593,6 +595,8 @@ int run_syscall(int min, int max)
 		CASE_TEST(fork);              EXPECT_SYSZR(1, test_fork()); break;
 		CASE_TEST(getdents64_root);   EXPECT_SYSNE(1, test_getdents64("/"), -1); break;
 		CASE_TEST(getdents64_null);   EXPECT_SYSER(1, test_getdents64("/dev/null"), -1, ENOTDIR); break;
+		CASE_TEST(gettimeofday_tv);   EXPECT_SYSZR(1, gettimeofday(&tv, NULL)); break;
+		CASE_TEST(gettimeofday_tv_tz);EXPECT_SYSZR(1, gettimeofday(&tv, &tz)); break;
 		CASE_TEST(getpagesize);       EXPECT_SYSZR(1, test_getpagesize()); break;
 		CASE_TEST(ioctl_tiocinq);     EXPECT_SYSZR(1, ioctl(0, TIOCINQ, &tmp)); break;
 		CASE_TEST(ioctl_tiocinq);     EXPECT_SYSZR(1, ioctl(0, TIOCINQ, &tmp)); break;