wifi: mac80211: add wiphy radio assignment and validation

Validate number of channels and interface combinations per radio.
Assign each channel context to a radio.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://patch.msgid.link/1d3e9ba70a30ce18aaff337f0a76d7aeb311bafb.1720514221.git-series.nbd@nbd.name


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