wifi: rtw89: 8922a: fix incorrect STA-ID in EHT MU PPDU

EHT MU PPDU contains user field of EHT-SIG field with STA-ID that
must match AID subfield in the Associate Response. Add a necessary
setting to prevent these from being inconsistent.

Signed-off-by: Kuan-Chung Chen <damon.chen@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20250217061235.32031-1-pkshih@realtek.com