Add ability to update I2C address before locking the config

[MartyMacGyver]

The default I2C address can be changed on the various ATECC108A/ECC508A/SHA204A/AES132A devices. This must happen before personalization is complete. Adding the ability to change the address would increase the flexibility of this tool.

Note that the address would need to be converted from the 7-bit format typically used on the Linux host to the 8-bit format on the device (i2c_addr_linux << 1 == i2c_addr_atmel).

Suggest 'n' (new-address) as the command, since 'a' (address) cannot be overloaded for this purpose.

[jbdatko]

Thanks. I'll start looking at this this week.