pcilmr: Move most of pcilmr arguments parsing logic to the separate file

pcilmr: Move most of pcilmr arguments parsing logic to the separate file

Also change arguments parsing logic: now link parameters (selected lane
numbers, timing or voltage steps, etc) need to be specified after link port
and will affect only this link margining (previously, one option was
applied to all links).

See updated man for syntax and example.

Signed-off-by: Nikita Proshkin <n.proshkin@yadro.com>