wifi: rtw89: update SER L2 type default value

8852BT after FW 0.29.127, 8852B after FW 0.29.128 and 8922A after FW
0.35.79, the SER L2 flow determines different L2 types by parameter,
the zero value will trigger FW SER L2 assert.

Signed-off-by: Chih-Kang Chang <gary.chang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20250710042423.73617-10-pkshih@realtek.com