odhcp6c: update to Git HEAD (2025-11-09)

odhcp6c: update to Git HEAD (2025-11-09)

17ef5f40d48a readme: rewrite in markdown
0fcfe9166173 readme: document all environment options
e3949977ca94 readme: update for prpl patch-set additions
86544fa2b581 src: align SoftAtHome license headers format
8bad7df9feb9 src: reorder includes alphabetically
6d353ff96826 src: remove pragma once in headers
f5684d570200 treewide: remove whitespaces at EOL
e5cfea8f6ef8 src: add missing if/else braces
a92f199d6b8d dhcpv6: potential bug fix for checking DHCPV6_OPT_STATUS
9e414d41e16e readme: fix description string
775e6c759cfd dhcpv6: return early upon success
e5690c1f13ed treewide: Replace _unused with _o_unused

This fixes the build on powerpc.

Signed-off-by: Hauke Mehrtens <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/20712
Signed-off-by: Christian Marangi <[email protected]>