Add tio to apt package prereqs

Bypass-Presubmit-Reason: no presubmit
Change-Id: I91c4703694bbba4920cc6e45329ed8f30ffdfe50
diff --git a/install-prereqs.sh b/install-prereqs.sh
index 28b640a..80d325e 100755
--- a/install-prereqs.sh
+++ b/install-prereqs.sh
@@ -94,6 +94,7 @@
     texlive-fonts-recommended
     texlive-latex-extra
     texlive-metapost
+    tio
     u-boot-tools
     uml-utilities
     polkitd