uboot: Update changelog to include the Hynix behavior change.

Change-Id: If23da93b6f3ca056a8b09387062494ed25e780f4
diff --git a/debian/changelog b/debian/changelog
index d3539d2..1acda3d 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,6 +1,7 @@
 uboot-imx (3-3) mendel-day; urgency=medium
 
   * Updating the training programs for Micron.
+  * Ensuring Hynix boards also use the same timing as Micron.
 
  -- Coral <coral-support@google.com>  Wed, 27 Mar 2019 15:21:16 -0700