phynode-kw41z/Makefile.include does not use the `common/kw41z/Makefile.include`

[cladmi]

Description

When migrated in 8bd320b it looks like the phynode-kw41z Makefile.include was not updated to use the new common/kw41z/Makefile.include as was for example done for frdm-kw41z 151803d

If it is a mistake, the board just need to be updated (not sure on my side), otherwise we have somehow an issue as partial common boards are a dangerous pattern.

Expected result

All the boards using common/kw41z use common/kw41z/Makefile.include.

Versions

Versions after #11044

Reference

Found while rebasing #11477

[aabadie]

It was made on purpose but after thinking of it a second time I came up with #11618.