wifi: rtw89: 8852b: change RF mode to normal mode when set channel

Set the RF mode from 0xA(low power mode) to 0x3(Normal mode) to avoid
abnormal TX waveform in OFDM rate. Originally the RF mode will be changed
to normal mode by the firmware after entering LPS once. Therefore, this
change does not affect power saving.

Signed-off-by: Chih-Kang Chang <gary.chang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20241030091603.6073-1-pkshih@realtek.com