poky.ent: Updated variable for "October 2018" string.

Manual revision history tables updated.

(From yocto-docs rev: c957e4ab60b4cf2778824162758b2b12bddcfafb)

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

documentation/poky.ent

@@ -8,7 +8,7 @@
 <!ENTITY YOCTO_DOC_VERSION_MINUS_ONE "2.5">
 <!ENTITY DISTRO_REL_TAG "yocto-2.6">
 <!ENTITY METAINTELVERSION "9.0">
-<!ENTITY REL_MONTH_YEAR "TBD">
+<!ENTITY REL_MONTH_YEAR "October 2018">
 <!ENTITY META_INTEL_REL_TAG "&METAINTELVERSION;-&DISTRO_NAME_NO_CAP;-&YOCTO_DOC_VERSION;">
 <!ENTITY POKYVERSION "21.0.0">
 <!ENTITY POKYVERSION_COMPRESSED "2100">