net80211: regdomain: ETSI: add missing 11a and 11na entries

The frequency range 5745-5865 (channels 149-173) wrongly has a
VHT160 channel listed (going up to 5885/177 which is not avail in
ETSI) but no 11a, 11na listed. Add the 11a and 11na in addition to
the 11ac 20/40 and 80.
Turns out the VHT40 entry for 5805-5845 was also missing. We already
had the neccessary setting for taiwan, so just adjust the freqband ref.

The problem is that without the 11a base channel ieee80211_find_channel()
in ieee80211_lookup_channel_rxstatus() will fail and sta_recv_mgmt() will
not get the correct channel but will use ic->ic_curchan (which is not
updated on scan offloading) and the scan result entry will be added as
channel 1.

Sponsored by: The FreeBSD Foundation
MFC after: 3 days
Reviewed by: adrian (previous version)
Differential Revision: https://reviews.freebsd.org/D51163