Alright, but you know the 8051 don’t have an in-built SPI module.
Since it also not having an ADC module, you might have interfaced the LM35 through an external ADC, right?
But there is nothing like external SPI module. Ofcourse you can simulate the SPI module using your code, and using few I/0 pins. Believe me its too difficult.
Better you choose a microcontroller having both ADC and SPI.
You WiFi board is a high end device, why are you trying to interface it with such a basic microcontroller?