doc: kernel: code-relocation: Document NOINIT memory type

The `zephyr_code_relocate` now supports the NOINIT memory type in addition
to DATA, TEXT and BSS. This patch documents its usage.

Signed-off-by: Joel Holdsworth <jholdsworth@nvidia.com>

Author: jhol

doc/kernel/code-relocation.rst

@@ -84,17 +84,18 @@ This section shows additional configuration options that can be set in
      zephyr_code_relocate(FILES src/file1.c LOCATION SRAM2)
      zephyr_code_relocate(FILES src/file2.c LOCATION SRAM)
 
-* If the memory type is appended with ``_DATA``, ``_TEXT``, ``_RODATA`` or
-  ``_BSS``, only the selected memory is placed in the required memory region.
-  For example:
+* If the memory type is appended with ``_DATA``, ``_TEXT``, ``_RODATA``,
+  ``_BSS`` or ``_NOINIT``, only the selected memory is placed in the required
+  memory region. For example:
 
   .. code-block:: none
 
      zephyr_code_relocate(FILES src/file1.c LOCATION SRAM2_DATA)
      zephyr_code_relocate(FILES src/file2.c LOCATION SRAM2_TEXT)
 
-* Multiple regions can also be appended together such as: ``SRAM2_DATA_BSS``.
-  This will place data and bss inside ``SRAM2``.
+* Multiple regions can also be appended together such as:
+  ``SRAM2_DATA_BSS_NOINIT``. This will place all data: value-initialized,
+  zero-initialized and uninitialized inside ``SRAM2``.
 
 * Multiple files can be passed to the ``FILES`` argument, or CMake generator
   expressions can be used to relocate a comma-separated list of files.