wifi: mt76: mt7921: update the channel usage when the regd domain changed

The 5.9/6GHz channel license of a certain platform device has been
regulated in various countries. That may be difference with standard
Liunx regulatory domain settings. In this case, when .reg_notifier()
called for regulatory change, mt792x chipset should update the channel
usage based on clc or dts configurations.

Channel would be disabled by following cases.
* clc report the particular UNII-x is disabled.
* dts enabled and the channel is not configured.

Signed-off-by: Ming Yen Hsieh <mingyen.hsieh@mediatek.com>
Co-developed-by: Deren Wu <deren.wu@mediatek.com>
Signed-off-by: Deren Wu <deren.wu@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>