wifi: rtw89: 8851b: adjust ADC setting for RF calibration

To get expected result of RF calibration at runtime, adjust ADC setting
ahead for coming changes of RF calibration.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20250627035201.16416-4-pkshih@realtek.com