Boards mtb4 and mtb4c: skin on the 5-th finger finally supported

[marcoaccame]

Description of activities

The work here is a follow up of a previous PR which showed some bugs.
namely, we:

• fix of CDC offset mapping
• aligned application versions when macro USE_FIFTH_I2C is defined

The combined effect of these two PRs is:

• the pin connected to the fifth I2C channel is activated by default
• the project as is compiles and gives a fully compatible binary file with the previous version reading only 4 I2C channels
• to use the fifth finger e.g. in ergocub class robots, we need:
  • open the project under ....\boards\mtbX\application\proj (X = 4 or 4c depending on the used board)
  • check the right version of comnpiler is selected (should be so) i.e. 6.19
  • open project options and in the C/C++ tab, define the USE_FIFTH_I2C macro
  • compile and eventually rename the binary file to distinguish it
  • at this point the binary file is ready to be flashed on the desired board, with either a programmer or the FirmwareUpdater tool
  • the correctness of operation can be checked from the version number which is offset by 50 wrt the official one
  • the configuration files are already aligned to this on ergocubSN001 on which the tests were done
    • the configuration may be summarized as:
    • turn off all triangles with cdcoffset = 2200
    • turn on only triangles 0 to 4 with cdcoffset = 0000

[simeonedussoni]

@marcoaccame I'd mark this as ready for review and merge, what do you think?

[marcoaccame]

@marcoaccame I'd mark this as ready for review and merge, what do you think?

Hi @simeonedussoni. The PR can be merged.