cleanup: include/: move misc/dlist.h to sys/dlist.h

move misc/dlist.h to sys/dlist.h and
create a shim for backward-compatibility.

No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.

Related to #16539

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
diff --git a/kernel/msg_q.c b/kernel/msg_q.c
index adf7dac..ef0bf43 100644
--- a/kernel/msg_q.c
+++ b/kernel/msg_q.c
@@ -17,7 +17,7 @@
 #include <linker/sections.h>
 #include <string.h>
 #include <wait_q.h>
-#include <misc/dlist.h>
+#include <sys/dlist.h>
 #include <misc/math_extras.h>
 #include <init.h>
 #include <syscall_handler.h>