tools/nolibc/gettimeofday: avoid libgcc 64-bit divisions

timespec::tv_nsec is going to be 64-bit wide even on 32-bit
architectures. As not all architectures support 64-bit division
instructions, calls to libgcc (__divdi3()) may be emitted by the
compiler which are not provided by nolibc.

As tv_nsec is guaranteed to always fit into an uint32_t, perform a
32-bit division instead.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20251220-nolibc-uapi-types-v3-6-c662992f75d7@weissschuh.net

tools/include/nolibc/sys/time.h

@@ -30,7 +30,7 @@ int sys_gettimeofday(struct timeval *tv, struct timezone *tz)
 	ret = sys_clock_gettime(CLOCK_REALTIME, &tp);
 	if (!ret && tv) {
 		tv->tv_sec = tp.tv_sec;
-		tv->tv_usec = tp.tv_nsec / 1000;
+		tv->tv_usec = (uint32_t)tp.tv_nsec / 1000;
 	}
 
 	return ret;