qcacld-3.0: Populate 6GHz channel list to wiphy

Use separate band - NL80211_BAND_6GHZ for 6GHz channel
list population. And 6GHz channels are reported only
when CFG80211_6GHZ_BAND_SUPPORTED and CONFIG_BAND_6GHZ
feature flags are defined.

Change-Id: Ieec30b304a7c3e8e856f290afdb4177206aeb2c7
CRs-Fixed: 2524262
3 files changed