Add missing definitions for QNX8 for several BPF-related structures and constants

[rafaeling]

Description

These structures are required for working with BPF filters and network interfaces on the QNX8 platform. Their absence currently prevents building or using BPF-related functionality with libc on QNX8 targets.

Sources

Updated src/unix/nto/mod.rs accordingly

Checklist

• [?] Relevant tests in libc-test/semver have been updated
  -> No tests for QNX?
• [*] No placeholder or unstable values like *LAST or *MAX are
  included (see #3131)
• [?] Tested locally (cd libc-test && cargo test --target mytarget); especially relevant for platforms that may not be checked in CI.
  -> even main branch does not work.
  Error: could not execute process /home/user/libc/target/x86_64-pc-nto-qnx800/debug/deps/libc-67e46525c5118905 (never executed)