wifi: rtw89: 8852b: set AMSDU limit to 5000

Enlarge AMSDU limit to improve MAC efficient to get better TX throughput
from 851 to 895 Mbps. No change for RX throughput 902 Mbps.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20240621123617.6687-1-pkshih@realtek.com