sysvipc: Fix 32-bit compat on !i386

The various time fields are time_t's which are only 32-bit on i386.

Fixing the old versions is probably of little use, but it's more correct
and in theory there could be powerpc binaries from 6.x.

PR: 240035
Fixes: fbb273bc05bef Properly support for FreeBSD 4 32bit System V shared memory.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D42870

(cherry picked from commit 957f014dc076a7f74ed0c8c8699e6f39b55785e7)