[PATCH] ref-manual: add "KERNEL_IMAGE_STRIP_EXTRA_SECTIONS" to variables

Add this variable to the variables glossary, and add links to it and
back to the do_strip() task for completeness.

Signed-off-by: Robert P. J. Day <[email protected]>

---

diff --git a/documentation/ref-manual/tasks.rst b/documentation/ref-manual/tasks.rst
index e1db2d5ed..ea0899f53 100644
--- a/documentation/ref-manual/tasks.rst
+++ b/documentation/ref-manual/tasks.rst
@@ -848,7 +848,7 @@ the kernel build produces a warning to that effect.
 ``do_strip``
 ------------

-If ``KERNEL_IMAGE_STRIP_EXTRA_SECTIONS`` is defined, this task strips
+If :term:`KERNEL_IMAGE_STRIP_EXTRA_SECTIONS` is defined, this task strips
 the sections named in that variable from ``vmlinux``. This stripping is
 typically used to remove nonessential sections such as ``.comment``
 sections from a size-sensitive configuration.
diff --git a/documentation/ref-manual/variables.rst b/documentation/ref-manual/variables.rst
index c92b195ff..1629df99f 100644
--- a/documentation/ref-manual/variables.rst
+++ b/documentation/ref-manual/variables.rst
@@ -5623,6 +5623,11 @@ system and gives an overview of their function and contents.

       See :term:`KERNEL_ARTIFACT_NAME` for additional information.

+   :term:`KERNEL_IMAGE_STRIP_EXTRA_SECTIONS`
+      If this variable is set, it should contain the sections to be
+      stripped from the ``vmlinux`` image by the kernel-related
+      :ref:`ref-tasks-strip` task.
+
    :term:`KERNEL_IMAGETYPE`
       The type of kernel to build for a device, usually set by the machine
       configuration files and defaults to "zImage". This variable is used