Documenation: Updated "Usually October" to "October 2017" string

The string in the manual revision table needed updated across the
set except for the kernel-dev manual.

(From yocto-docs rev: e087a707e02ff913baba2ac8bc6594206f53f70c)

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

documentation/bsp-guide/bsp-guide.xml

@@ -120,7 +120,7 @@
             </revision>
             <revision>
                 <revnumber>2.4</revnumber>
-                <date>Usually October</date>
+                <date>October 2017</date>
                 <revremark>Released with the Yocto Project 2.4 Release.</revremark>
             </revision>
         </revhistory>

documentation/dev-manual/dev-manual.xml

@@ -98,7 +98,7 @@
             </revision>
             <revision>
                 <revnumber>2.4</revnumber>
-                <date>Usually October</date>
+                <date>October 2017</date>
                 <revremark>Released with the Yocto Project 2.4 Release.</revremark>
             </revision>
         </revhistory>

documentation/kernel-dev/kernel-dev-intro.xml

@@ -37,6 +37,12 @@
         latest from the
         <ulink url='&YOCTO_HOME_URL;/organization/long-term-support-initiative-ltsi'>Long Term Support Initiative</ulink>
         (LTSI) project.
+        You can learn more about Yocto Linux kernels and LTSI in the
+        "<link linkend='kernel-big-picture'>Yocto Project Kernel Development and Maintenance</link>"
+        section.
+    </para>
+
+    <para>
         Also included is a Yocto Linux kernel development recipe
         (<filename>linux-yocto-dev.bb</filename>) should you want to work
         with the very latest in upstream Yocto Linux kernel development and

documentation/mega-manual/mega-manual.xml

@@ -67,7 +67,7 @@
             </revision>
             <revision>
                 <revnumber>2.4</revnumber>
-                <date>Usually October</date>
+                <date>October 2017</date>
                 <revremark>Released with the Yocto Project 2.4 Release.</revremark>
             </revision>
        </revhistory>

documentation/profile-manual/profile-manual.xml

@@ -83,7 +83,7 @@
             </revision>
             <revision>
                 <revnumber>2.4</revnumber>
-                <date>Usually October</date>
+                <date>October 2017</date>
                 <revremark>Released with the Yocto Project 2.4 Release.</revremark>
             </revision>
         </revhistory>

documentation/ref-manual/ref-manual.xml

@@ -114,7 +114,7 @@
             </revision>
             <revision>
                 <revnumber>2.4</revnumber>
-                <date>Usually October</date>
+                <date>October 2017</date>
                 <revremark>Released with the Yocto Project 2.4 Release.</revremark>
             </revision>
         </revhistory>

documentation/sdk-manual/sdk-manual.xml

@@ -48,7 +48,7 @@
             </revision>
             <revision>
                 <revnumber>2.4</revnumber>
-                <date>Usually October</date>
+                <date>October 2017</date>
                 <revremark>Released with the Yocto Project 2.4 Release.</revremark>
             </revision>
        </revhistory>

documentation/toaster-manual/toaster-manual.xml

@@ -58,7 +58,7 @@
             </revision>
             <revision>
                 <revnumber>2.4</revnumber>
-                <date>Usually October</date>
+                <date>October 2017</date>
                 <revremark>Released with the Yocto Project 2.4 Release.</revremark>
             </revision>
        </revhistory>