subsystems: migrate includes to <zephyr/...>

In order to bring consistency in-tree, migrate all subsystems code to
the new prefix <zephyr/...>. Note that the conversion has been scripted,
refer to zephyrproject-rtos#45388 for more details.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>

subsys/demand_paging/backing_store/backing_store_qemu_x86_tiny.c

@@ -18,8 +18,8 @@
 #include <mmu.h>
 #include <string.h>
 #include <kernel_arch_interface.h>
-#include <linker/linker-defs.h>
-#include <sys/util.h>
+#include <zephyr/linker/linker-defs.h>
+#include <zephyr/sys/util.h>
 
 void *location_to_flash(uintptr_t location)
 {

subsys/demand_paging/eviction/nru.c

@@ -5,10 +5,10 @@
  *
  * Not Recently Used (NRU) eviction algorithm for demand paging
  */
-#include <kernel.h>
+#include <zephyr/kernel.h>
 #include <mmu.h>
 #include <kernel_arch_interface.h>
-#include <init.h>
+#include <zephyr/init.h>
 
 /* The accessed and dirty states of each page frame are used to create
  * a hierarchy with a numerical value. When evicting a page, try to evict