wifi: rtw89: mac: define register address of rx_filter to generalize code

rx_filter is used to decide which kind of packets are received to driver,
or just dropped by MAC layer to reduce bus traffic.

The bit definitions of old and new chips are the sames, but only address
is changed, so define a field to generalize usage.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230822125822.23817-5-pkshih@realtek.com