wifi: mac80211: add radio index to ieee80211_chanctx_conf

Will be used to explicitly assign a channel context to a wiphy radio.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://patch.msgid.link/59f76f57d935f155099276be22badfa671d5bfd9.1720514221.git-series.nbd@nbd.name


Signed-off-by: Johannes Berg <johannes.berg@intel.com>