Move thread monitor related functions, not enabled in most cases outside
of thread.c and cleanup headers.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Move out of thread and put directly in init.c where it is being used.
Also remove definition from kernel.h, this is an internal function and
should not be in a public header.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>