Add an errata entry for J1900 systems that require kern.vty=sc

at the loader(8) prompt.

Submitted by:	phk
Sponsored by:	The FreeBSD Foundation

en_US.ISO8859-1/htdocs/releases/12.0R/errata/errata.xml

@@ -93,7 +93,20 @@
   <sect1 xml:id="open-issues">
     <title>Open Issues</title>
 
-    <para>No open issues.</para>
+    <itemizedlist>
+      <listitem>
+	<para>[2018-12-11] Some &intel; J1900 systems may hang on boot
+	  in <acronym>UEFI</acronym> mode.  An observed workaround is
+	  to set <literal>kern.vty=sc</literal> at the &man.loader.8;
+	  prompt.  To have the setting persist after &man.reboot.8;,
+	  add <literal>kern.vty=sc</literal> to
+	  &man.loader.conf.5;.</para>
+
+	<para>See <acronym>PR</acronym> <link
+	    xlink:href="https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=230172">230172</link>
+	  for more information.</para>
+      </listitem>
+    </itemizedlist>
   </sect1>
 
   <sect1 xml:id="late-news">