The board amcbldc upgrades its low level HW motor driver

[marcoaccame]

This PR upgrades the amcbldc project to use a new low level HW motor driver, the so called motorhal.

The motorhal is code written on top of the ST HAL library which configures and uses HW peripherals such ADC and TIM to read currents, voltages and to produce the PWM for the motor.

The new motorhal2 has been improved over the legacy motorhal to use a new version of ST HAL and some improved configurations of the HW peripherals.

At the same time the legacy driver has been mildly refactored.

The new project can use either the legacy or the new driver to enable comparative tests.

In the following figure is show what has changed.

   ---------------------------
  | model based motor control | <- unchanged
   ---------------------------
  | embot::hw::motor          | <- almost unchanged
   ---------------------------  
   ---------------------------
  | motorhal                  | <- either motorhal or motorhal2
   ---------------------------  
   ---------------------------
  | STM HAL                   | <- either v120 or v122
   --------------------------- 
   

Figure. Changes in the motor control stack in amcbldc.

Tests

Test were performed and showed similar behaviour w/ the previous HW motor drivers. So we can safely merge. In any case, I have kept the previous drivers as an alternative target in the amcbldc project.

[sgiraz]

@marcoaccame and I tested successfully both the intermediate v1.1.10 and the definitive v1.2.10 FWs on the wrist-setup.
Now we have to acquire some quantities to catch the differences between the old v1.0.9 and the new v1.2.10.

cc @Nicogene @pattacini @mfussi66