Further jtag2updi improvement

[mcuee]

There are some suggestions from @askn37 to improve jtag2updi. He has also patched FW for his jtag2updi implementation.

[mcuee]

To do: to mention about the improvements which are good to have.

[mcuee]

Existing issue #1661 which was fixed by #1662.

• The last write/erase can fail with -c jtag2updi #1661
• Read the signature on -c jtag2updi exit if last op was write/erase #1662

[mcuee]

@askn37's improved jtag2updi firmware
https://github.com/askn37/jtag2updi/

[mcuee]

@MCUdude
The above jtag2updi fork supports to be installed on older AVRs, and it suports new UPDI AVRs, similar to serialupdi.

Equipment that can be installed with firmware:

ATmegaX8 series --- Arduino UNO Rev.3, Arduino Mini, Arduino Micro (ATmega328P)
megaAVR-0 series --- Arduino UNO WiFi Rev.2 (ATmega4809)
AVR_DA/DB Series --- Microchip Curiocity

• Compatible with NVMCTRL version 0,2,3,4,5. The correspondence in the original text is up to 0 and 2.. Support tinyAVR-0/1/2, megaAVR-0, AVR_DA/DB/DD/EA/EB.
• Compatible with AVRDUDE 7.3

I will try the above using Arduno Uno Rev 3 clones.

[mcuee]

@askn37 has another repo but that can not be installed on the older AVRs.
https://github.com/askn37/multix-zinnia-updi4avr-firmware-builder/