tools/nolibc: fall back to sys_clock_gettime() in gettimeofday()

tools/nolibc: fall back to sys_clock_gettime() in gettimeofday()

Newer architectures (like riscv32) do not implement sys_gettimeofday().
In those cases fall back to sys_clock_gettime().
While that does not support the timezone argument of sys_gettimeofday(),
specifying this argument invokes undefined behaviour, so it's safe to ignore.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250428-nolibc-misc-v2-14-3c043eeab06c@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>