Modify EEPROM functions to manage not only multiples of 4 inputs

[cua-cua]

The EEPROM functions (save and read) only manage input data multiple of 4 because the data is flashed with flash_program_word function. We have two alternatives:

• Discard the data that can not be saved on words (current solution)
• Include garbage data so the data always is contained on words. (proposed solution)

At this moment we only save maze sequence of 16*16 size so this is not a bug yet.

[cua-cua]

• Change EEPROM read and save functions to have uint32_t pointer as input and output data.
  (Fom review comment: it is a bit more consistent within the loop, as you would not need BYTES_PER_WORD and could increment output_data++ or use (output_data + iter) (just like you do with memory_ptr)