OTA implementation & fixes for RTL8720CF

[prokoma]

I've cleaned the history and removed the code to pull ltchiptool from git. You need to make a release of ltchiptool first before merging this PR and also update the minimum required version in builder/main.py.

[prokoma]

Hi @fcol95,
OTA for rtl8720cf is not implemented yet in the official release. My solution works, but the code is not ideal and there are some open questions.

I've described steps how to install esphome with working OTA in #44 (comment) . You can skip step 0, because ltchiptool >= 4.11.5 already contains the mentioned fix.

[fcol95]

@prokoma thanks for your quick reply, just had deleted my comment when stumbling on your open PR in ltchiptool repo and understanding a bit better the issue! thanks for the link to your custom solution!
I'll give it a go once I finish working on the component driver I need to do for the chip that interfaces with this rtl8720c in my device!

[fcol95]

Just tested the OTA through esphome and your "source: https://github.com/prokoma/libretiny#55aacc8" framework, works quite well, thanks for the effort, would be glad to see that merged in the production release soon!