rtw89: Skip useless dig gain and igi related settings for 8852C

Separated DIG RX gain, IGI configurations from not supportted HW using
"support_igi" capability flag.

Signed-off-by: Johnson Lin <johnson.lin@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220408001353.17188-9-pkshih@realtek.com