Two simple drivers that provide and consume an exported symbol.
Export your symbols using EXPORT_GPL_SYMBOL or EXPORT_SYMBOL as normal.
Build your provider module as normal - and take a look at the Module.symvers file as we're going to depend on what it exports - the Makefile contains the magic part.
Your dependent module will now need a makefile that uses KBUILD_EXTRA_SYMBOLS in order to reference these additional symbols