wifi: rtw89: 8852b: add chip_ops to get thermal

Thermal value reflects temperature that will affect RF performance, so
we re-calibrate RF characteristics if delta of thermal over a threshold.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20221009125403.19662-5-pkshih@realtek.com