Add warning about Wi-Fi

[nikp123]

This module seems to kill Wi-Fi on my PSP-1000.
When I try to enter the Network setup and select Infrastructure, one of the following happens:

1. The PSP freezes (though this is extremely rare)
2. Gets stuck for 10s and throws an error

Disabling the module through Recovery mode seems to fix the issue.

[nikp123]

Given that it's streaming video, I bet the PSP is running out of RAM, since it's the 1000 model, instead of the 2000, 3000 or GO that all have double the RAM.