wifi: rtw89: limit the PPDU length for VHT rate to 0x40000

wifi: rtw89: limit the PPDU length for VHT rate to 0x40000

If the PPDU length for VHT rate exceeds 0x40000, calculating the PSDU
length will overflow. TMAC will determine the length to be too small and
as a result, all packets will be sent as ZLD (Zero Length Delimiter).

Fixes: 5f7e92c59b8e ("wifi: rtw89: 8852b: set AMSDU limit to 5000")
Signed-off-by: Chia-Yuan Li <leo.li@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20240815134054.44649-1-pkshih@realtek.com