When using GOLDENBOARD is not possible to flash the test fw on the cores

[MSECode]

When testing with the GOLDENBOARD only it is not possible to flash on the board the test bootloader and firmware using the test equipment since those steps are not present in the phase2 of the testing procedure. However, since might be quite helpful to re-flash test bl and fw when running the phase2 using the goldenboard we are going to add those steps to the phase2 as well.

cc: @valegagge

[MSECode]

This PR https://github.com/icub-tech-iit/electronics-legacy/pull/80 brings the updates for solving this issue too.
Basically, I've added the steps for flashing the test fw also at the beginning of fase2.xml, which is the only xml that can be completely run if using a goldenboard.

[valegagge]

I put on hold this issue until the test equipment is available