wifi: rtw89: 8851b: rfk: update TX wideband IQK

Adjust TX wideband calibration from 1 to 2 loop gain settings.
This can reflect in better performance in 5 GHz medium-high
attenuation environments.

Signed-off-by: Kuan-Chung Chen <damon.chen@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20250811123913.15524-1-pkshih@realtek.com