wifi-scripts: add missing dependency on ucode-mod-rtnl

wifi-scripts: add missing dependency on ucode-mod-rtnl

rtnl is used in hostap/common.uc.

$ grep -r rtnl files
files/usr/share/hostap/common.uc:import * as rtnl from "rtnl";
files/usr/share/hostap/common.uc:	     rtnl.request(rtnl.const.RTM_SETLINK, 0, { dev: reuse_ifname, ifname: name}) != false))
files/usr/share/hostap/common.uc:	rtnl.request(rtnl.const.RTM_SETLINK, 0, { dev: name, change: 1, flags: up ? 1 : 0 });

Signed-off-by: FUKAUMI Naoki <naoki@radxa.com>
Link: https://github.com/openwrt/openwrt/pull/15922
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>