kernel: remove placeholder vm subsystem

vm/vm_bootstrap.c

@@ -1,6 +0,0 @@
-#include <socks/status.h>
-
-kern_status_t vm_bootstrap(void)
-{
-	return KERN_ERR_UNIMPLEMENTED;
-}

vm/vm_map.c

@@ -1,7 +0,0 @@
-#include <socks/vm.h>
-#include <stddef.h>
-
-vm_map_t *vm_map_create(void)
-{
-	return NULL;
-}

vm/vm_object.c

@@ -1,7 +0,0 @@
-#include <socks/vm.h>
-#include <stddef.h>
-
-vm_object_t *vm_object_create(void)
-{
-	return NULL;
-}

vm/vm_page.c

@@ -1,6 +0,0 @@
-#include <socks/vm.h>
-
-void vm_page_init(vm_page_t *page)
-{
-
-}