In ACPI SAR enabled device, mt7921 should read power limit in ACPI config.
The limit value would be applied to regular tx power settings in mt76.

Two major functionalities added:
1. Get SAR power table through ACPI.
2. Read power in Dynamic/Geo SAR table for tx power limit.

Table note
MTDS: Dynamic SAR table
MTGS: Geo SAR table
MTCL: Country List table (for 6GHz support)
Reviewed-by: Sean Wang <sean.wang@mediatek.com>
Co-developed-by: Quan Zhou <quan.zhou@mediatek.com>
Signed-off-by: Quan Zhou <quan.zhou@mediatek.com>
Co-developed-by: Ming Yen Hsieh <mingyen.hsieh@mediatek.com>
Signed-off-by: Ming Yen Hsieh <mingyen.hsieh@mediatek.com>
Signed-off-by: Deren Wu <deren.wu@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>