rtw89: use hardware SSN to TX management frame

Since firmware transmits beacon by hardware SSN, driver does it with the
same setting, then packets in the air have continual sequence number.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220107034239.22002-3-pkshih@realtek.com