replace parport component with sim_parport

better descriptive name
adjust stepconf to use new name

Signed-off-by: Chris Morley <chrisinnanaimo@hotmail.com>
remove parport component

Signed-off-by: Chris Morley <chrisinnanaimo@hotmail.com>
sim_axis_hardware -remove home-all selection pins, add docs

with apropriate defaults, home-all selection is not required,
the unused axes will not trip home-all because the position stays at zero.

docs are probably helpful...

Signed-off-by: Chris Morley <chrisinnanaimo@hotmail.com>