wifi: rtw89: mac: use mac_gen pointer to access about efuse

Use function pointers to abstract efuse access, and introduce an new
function to convert efuse power state that is needed by WiFi 7 chips.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20231117024029.113845-3-pkshih@realtek.com