wifi: rtw89: regd: judge 6 GHz according to chip and BIOS

We allow platform to disable 6 GHz on chips, which supports 6 GHz, through
BIOS. Driver will evaluate Realtek acpi DSM with RTW89_ACPI_DSM_FUNC_6G_DIS
(function 3) to get whether 6 GHz should be disabled.

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/20230602150556.36777-3-pkshih@realtek.com