Support for other ESP32 variants (C3, etc)

[RoganDawes]

It would be really great to have support for other ESP32 chip variants, in particular the RISC-V-baed chips. I got the first step of selecting the "esp32c3" in LoadFirmwareImage, but still need to figure out the processor family changes required from EXTENSA to RISCV, etc.

[RoganDawes]

So makeelf 0.35 now has constants for the RISCV family, which lets me get a tiny bit further. Will keep poking at this.

[delfer]

any news?)

[RoganDawes]

Not from me, I'm afraid. The project that I needed it for was cancelled (Sunsynk pushed a fix to their fleet of WiFi dongles).

[delfer]

Anybody here can check this PR #12