wifi: mac80211: Fix setting txpower with emulate_chanctx

Propagate hw conf into the driver when txpower changes
and driver is emulating channel contexts.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Link: https://patch.msgid.link/20240924011325.1509103-1-greearb@candelatech.com


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