kernel-dev: Added note about running a clean build with a patch

Put this note at the end of the traditional kernel development
flow.  A way for the user to verify that the patch was applied
for a subsequent build.

(From yocto-docs rev: 598a518cd92980e1781649a3ed30ac585327dc0f)

Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/kernel-dev/kernel-dev-common.xml

@@ -1434,6 +1434,21 @@
                     You can also see the
                     "<ulink url='&YOCTO_DOCS_DEV_URL;#using-bbappend-files'>Using .bbappend Files in Your Layer"</ulink>"
                     section in the Yocto Project Development Manual.
+                    <note>
+                        To build <filename>core-image-minimal</filename>
+                        again and see the effects of your patch, you can
+                        essentially eliminate the temporary source files
+                        saved in <filename>poky/build/tmp/work/...</filename>
+                        and residual effects of the build by entering the
+                        following sequence of commands:
+                        <literallayout class='monospaced'>
+     $ cd ~/poky/build
+     $ cd bitbake -c cleanall yocto-linux
+     $ cd bitbake core-image-minimal -c cleanall
+     $ bitbake core-image-minimal
+     $ runqemu qemux86
+                        </literallayout>
+                    </note>
                     </para></listitem>
             </orderedlist>
         </para>