Documentation: Updated dates for 2.5.2 release.

Updated the variable in poky.ent.

(From yocto-docs rev: ae0fb9ef999478e03cd93a9e8e18700e7707c6fd)

(From poky rev: 623b77885051174d0e05198843e739110977bd18)

Change-Id: If4c24ee93a1244ec227d5f5d89d4b0d761889680
Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/poky/documentation/poky.ent b/poky/documentation/poky.ent
index f629fd4..1b71b80 100644
--- a/poky/documentation/poky.ent
+++ b/poky/documentation/poky.ent
@@ -8,7 +8,7 @@
 <!ENTITY YOCTO_DOC_VERSION_MINUS_ONE "2.4.4">
 <!ENTITY DISTRO_REL_TAG "yocto-2.5.2">
 <!ENTITY METAINTELVERSION "9.2">
-<!ENTITY REL_MONTH_YEAR "TBD">
+<!ENTITY REL_MONTH_YEAR "December 2018">
 <!ENTITY META_INTEL_REL_TAG "&METAINTELVERSION;-&DISTRO_NAME_NO_CAP;-&YOCTO_DOC_VERSION;">
 <!ENTITY POKYVERSION "20.0.2">
 <!ENTITY POKYVERSION_COMPRESSED "2002">