wifi: rtw89: Introduce Time Averaged SAR (TAS) feature

Time Averaged SAR (TAS) tracks the amount of transmit power over a
period of time and adjusts the power accordingly. Two thresholds are
used to determine when to increase or reduce transmit power: Dynamic
Power Reduction (DPR) on/off. Compared to Static SAR, which has a
constant transmit power, TAS can improve the user experience or
range extension.

TAS can be enabled through BIOS, and the driver will evaluate
Realtek ACPI DSM with RTW89_ACPI_DSM_FUNC_TAS_EN to determine
whether TAS should be enabled.

Signed-off-by: Kuan-Chung Chen <damon.chen@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/20230804053458.31492-1-pkshih@realtek.com