scripts: zephyr_module: Add variable with module path

Adds a variable that has the path of the module directory, this
is supplied as an argument when running cmake normally but is
not supplied when running the check compliance script, this
addition allows checks to be ran that use such syntax in Kconfig
files. This is then removed from cmake as the python file handles
it instead

Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>