Multilevel interrupt configs are leaking into every single build without
this option being enabled, so guard the Kconfig and include files to
avoid this.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Move include paths and add new target_include_directories to support
backwards compatibility:
* /include -> /include/zephyr
example: <irq.h> -> <zephyr/irq.h>
Issue #41543
Signed-off-by: Yuval Peress <peress@google.com>