linux: Remove time64-support

It breaks the usage case of live migration like CRIU or similar
and most usages can be optimized away by either building glibc with
a minimum 5.1 kernel or by using the 32-bit syscall for the common
case.

Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.

Reviewed-by: Lukasz Majewski <lukma@denx.de>