wifi: rtw89: concentrate chandef setting to stack callback

Originally, we didn't support mac80211 chanctx, so it's expected that
ieee80211_hw::conf::chandef would be filled by mac80211. And then, we
could just query it whenever we need the current chandef.

However, we are planing to support mac80211 chanctx. After that, the
above assumption would be broken. So, we adjust a bit ahead to reduce
future works about mac80211 chanctx.

After this, we don't query ieee80211_hw::conf::chandef directly, and
we add a map, entity_map, to HAL to indicate which chandef came from
stack. And it will later be used to recalcate entity mode.

Signed-off-by: Zong-Zhe Yang <kevin_yang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220809104952.61355-9-pkshih@realtek.com