MAX72xx matrix display implementation

I have added support for MAX72xx matrix displays (like the Handsontec MAX7219 32x8 Dot Matrix Display Module).

Tested with Arduino Mega 2560 and MD_MAX72xx library. Hardware type must be set to MD_MAX72XX::FC16_HW.

Attached patch and example.

Best regards.

Cool !! Thanks.

You should use your name in the copyright notice in the files.
Same applies to AIP31068 LCD.

if you want send me a PM with your data to update it.

Updated patch (discard previous) to match default MAX72xx register values to power-up values.

Also corrected intensity calculation and included example to test it.

Best regards.