kernelshark: generate header file in the build directory

Mixing versioned and generated files will bloat git listings.
Put KsCmakeDef.hpp together with the rest of the generated files.

Signed-off-by: Mircea Cirjaliu <mircea.cirjaliu@yahoo.com>
Signed-off-by: Yordan Karadzhov <y.karadz@gmail.com>