We are planning to support mac80211 chanctx. To reduce future works,
the driver architecture is adjusted first to isolate related things.

According to chip, our HW may have multiple sub-entities to support
multiple mac80211 chanctx. Struct rtw89_chan has been introduced for
things about channel/band/subband/... Now introduce struct rtw89_chan_rcd
to record difference after assigning new one of struct rtw89_chan.

We will implement and support chanctx with single channel first, i.e.
only use entry in RTW89_SUB_ENTITY_0, before handling dual channels.

Our hierarchy in planning will become as the following.
DEV
-> HAL
---> entity (manage status across sub-entities)
-----> sub-entity[*] (support mac80211 chanctx)
where each sub-entity contains one struct rtw89_chan.
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/20220809104952.61355-4-pkshih@realtek.com