wifi: mac80211_hwsim: add support for multi-radio wiphy

This registers one wiphy radio per supported band. Number of different
channels is set per radio.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://patch.msgid.link/3a16838bb7a7d1a072bd7c9d586d17f70fcd8a60.1720514221.git-series.nbd@nbd.name


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