doc: build infodocs target on Gitlab CI, Azure

Add infodocs target to CI testing.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/.azure-pipelines.yml b/.azure-pipelines.yml
index 5fe3b87..49fc34f 100644
--- a/.azure-pipelines.yml
+++ b/.azure-pipelines.yml
@@ -76,8 +76,8 @@
     steps:
       - script: cppcheck -j$(nproc) --force --quiet --inline-suppr .
 
-  - job: htmldocs
-    displayName: 'Build HTML documentation'
+  - job: docs
+    displayName: 'Build documentation'
     pool:
       vmImage: $(ubuntu_vm)
     container:
@@ -89,6 +89,7 @@
           . /tmp/venvhtml/bin/activate
           pip install -r doc/sphinx/requirements.txt
           make htmldocs
+          make infodocs
 
   - job: todo
     displayName: 'Search for TODO within source tree'