rtw88: config 8822c multicast address in MAC init flow

Multicast address should be congiured in the initialization flow.
The value is created by a hashed calculation that is also implemented
by the hardware for multicast address filtering.

Signed-off-by: Tzu-En Huang <tehuang@realtek.com>
Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>