Looking these drivers over, all of them cannot build without access to some platform specific header files. Express those requirements in Kconfig as well. Furthermore, update the logic a bit more to reflect which parts are optional when other drivers are enabled and which parts cannot be enabled (meaningfully) by themselves. Reviewed-by: Svyatoslav Ryhel <clamor95@gmail.com> Signed-off-by: Tom Rini <trini@konsulko.com>