boards: v2: doc: Add vendors

Minimum modification to make boards doc visible in v2 model.

Signed-off-by: Erwan Gouriou <erwan.gouriou@st.com>

boards/index.rst

@@ -33,8 +33,12 @@ available under :zephyr_file:`doc/templates/board.tmpl`.
    v2/arm/index.rst
    v2/gaisler/index.rst
    v2/gd/index.rst
+   v2/google/index.rst
+   v2/others/index.rst
    v2/qemu/index.rst
    v2/raspberry_pi/index.rst
    v2/renesas/index.rst
+   v2/seagate/index.rst
    v2/sparkfun/index.rst
+   v2/st/index.rst
    v2/wiznet/index.rst

boards/v2/google/index.rst

@@ -0,0 +1,10 @@
+.. _boards-google:
+
+Google
+######
+
+.. toctree::
+   :maxdepth: 1
+   :glob:
+
+   **/*

boards/v2/others/index.rst

@@ -0,0 +1,10 @@
+.. _boards-others:
+
+Other and unknown vendors
+#########################
+
+.. toctree::
+   :maxdepth: 1
+   :glob:
+
+   **/*

boards/v2/st/index.rst

@@ -0,0 +1,10 @@
+.. _boards-st:
+
+STMicroelectronics
+##################
+
+.. toctree::
+   :maxdepth: 1
+   :glob:
+
+   **/*