1. Just simple to check the linux kernel source ,the module include flag.
example 1 : some kernel source using "EXTRA_FLAGS" to add include path or macro when kernel module build.
example 1 : some kernel source using "CFLAGS_MODULE" to add include path or macro when kernel module build.
2. Check the kernel driver source , there must have some example to add extra include path example,especially those driver which have multiple floder/path.
