Renumber endpoints for only chosen USB interfaces; fix HID report ids

[dhalbert]

• Endpoint renumbering was done over all the possible USB devices, not the selected ones.
• Handling of no report ID when only one HID devices was incorrect.
• Reordered where to put HID in descriptor (just for consistency).

[hierophect]

While it looks conceptually fine to me I'm not an experienced enough Python coder to notice issues with the implementation. I'd recommend having at least one other person check it out.

[hierophect]

Conceptually fine but I'd double check with a python person.

[dhalbert]

@hierophect can you test it on STM32F412 with reduced USB devices to see if the Windows enumeration problem crops up? I can give you a build if you want.

[hierophect]

@dhalbert sure can you pass me a binary?

[dhalbert]

I tested this on a '412 board, using the commit from #2132 just before this commit d8251ae. Works fine on Linux and Windows.

[ladyada]

thank you!

[dhalbert]

Fixes bugs in #2116.