BUILD: fix compilation on NetBSD

BUILD: fix compilation on NetBSD

Use include file <sys/time.h> to fix compilation error with timeval in
some files. This is as reported as 'man 7 system_data_types'. The build
error is reported on NetBSD 9.2.

This should be backported up to 2.2.

(cherry picked from commit 28c5b3c0bc40f96579845f13a9fafa6f63eb10c0)
[wt: only applied to check-t.h]
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 08fc157c389572ae49a1c80d85df242074e4d2bb)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>