tools/nolibc: Get timeval, timespec and timezone from linux/time.h

tools/nolibc: Get timeval, timespec and timezone from linux/time.h

The definitions of timeval(), timespec() and timezone() conflict with
linux/time.h when building, so this commit takes them directly from
linux/time.h. This is a port of nolibc's upstream commit dc45f5426b0c
to the Linux kernel.

Fixes: 66b6f755ad45 ("rcutorture: Import a copy of nolibc")
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>