Revert "poky: subtree update:b23aa6b753..ad30a6d470"

This reverts commit af5e4ef732faedf66c6dc1756432e9de2ac72988.

This commit introduced openbmc/openbmc#3720 and no solution has been
forthcoming. Revert until we can get to the bottom of this.

Change-Id: I2fb0d81eb26cf3dadb2f2abdd1a1bb7a95eaf03c
diff --git a/poky/bitbake/doc/sphinx-static/theme_overrides.css b/poky/bitbake/doc/sphinx-static/theme_overrides.css
index e362677..4fd76a1 100644
--- a/poky/bitbake/doc/sphinx-static/theme_overrides.css
+++ b/poky/bitbake/doc/sphinx-static/theme_overrides.css
@@ -4,6 +4,8 @@
 
 body {
   font-family: Verdana, Sans, sans-serif;
+
+  min-width: 640px;
   margin:  0em auto;
   color: #333;
 }