kernel: Add missing include

These files were using z_thread_malloc() without including
kernel_internal.h.  On existing architectures that works due to
transitive includes, but x86_64 has a thinner include layer and
doesn't do it for us.  Include the files required for the APIs we use.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>

kernel/msg_q.c

@@ -20,6 +20,7 @@
 #include <misc/dlist.h>
 #include <init.h>
 #include <syscall_handler.h>
+#include <kernel_internal.h>
 
 extern struct k_msgq _k_msgq_list_start[];
 extern struct k_msgq _k_msgq_list_end[];

kernel/pipes.c

@@ -20,6 +20,7 @@
 #include <init.h>
 #include <syscall_handler.h>
 #include <misc/__assert.h>
+#include <kernel_internal.h>
 
 struct k_pipe_desc {
 	unsigned char *buffer;           /* Position in src/dest buffer */

kernel/queue.c

@@ -21,6 +21,7 @@
 #include <misc/sflist.h>
 #include <init.h>
 #include <syscall_handler.h>
+#include <kernel_internal.h>
 
 extern struct k_queue _k_queue_list_start[];
 extern struct k_queue _k_queue_list_end[];

kernel/stack.c

@@ -18,6 +18,7 @@
 #include <misc/__assert.h>
 #include <init.h>
 #include <syscall_handler.h>
+#include <kernel_internal.h>
 
 extern struct k_stack _k_stack_list_start[];
 extern struct k_stack _k_stack_list_end[];