Cannot include header files from sys/contrib directory

Hello all,

I'm trying to include header files in the networking driver under sys/dev/,
however the headers are located in sys/contrib directory.
Does anyone have a clue or an advice on how to do this properly without
making too much trouble in the build system?
I would prefer to avoid changing content of the header files.

I tried adding 'compile-with' + '-I' flags in files but that did not work
as expected.

Thank you in advance for your help.

Marcin Mazurek