Add basic support for the Wi-Fi peripheral on the ESP32.

[Frostie314159]

Hi, this PR adds an SVD patch for the WiFi peripheral. It is based on reverse engineering efforts, by the esp32-open-mac project. I have tested these, by building a driver for the WiFi peripheral.
Status:

• RX
• TX
• Rate setting
• HT Rates
• RX filtering
  The following will be implemented in a future PR.
• Crypto (partial and untested)
• Sleep
• CSI
• Promiscuous Mode
• Long Range mode (Or at least the MAC specific parts of it)
• Hardware statistics
• Block ACK
• AMPDU
• Probably some I forgot

For examples and tests, see https://github.com/esp32-open-mac/esp32-wifi-hal-rs

[Frostie314159]

I've decided to reduce the scope of this PR a little, since I would love for Ferris-on-Air to be able to run on an unpatched version of esp-hal. Therefore, the current state of this PR can be seen as an MVP, which I'll extend with further PR's. I hope this is fine for everyone.
Before marking this as ready for review, I'll temporarily remove crypto support, since that's the only untested part of this SVD.

[Frostie314159]

I have moved crypto support to another branch, the rest of this is tested and in active use. In the future, I'll reorganize the individual components of this, like TX/RX, RX filtering, etc. into common patch files, which we can then just relocate for the other chip variants. RX and TX are extremely similar across chips, as well as the filtering, so we can support more chips that way in the future.
Also thanks a lot for considering this PR, seeing that these patches aren't official but reverse engineered knowledge!

[jessebraham]

This all looks reasonable enough to me, though we are peering into a black box 😅

Really great work on this so far, I'm glad to hear you have something usable already! Looking forward to following your work :)

[Frostie314159]

Thanks a lot for merging this! I will make a PR for esp-hal later today, updating the PACs and making the Wi-Fi peripheral non-virtual.