nl80211: Read reg-domain information from a specific wiphy

nl80211: Read reg-domain information from a specific wiphy

If driver supports self-managed regulatory domain, read reg-domain
information for that specific wiphy interface instead the global
information which may be different which such drivers. This fixes issues
where a regulatory update with a self-managed regulatory domain driver
ended up building incorrect list of supported channels for upper layer
hostapd/wpa_supplicant operations.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>