doc: boards: amlogic: add documentation for KII Pro

Add build instructions for the KII Pro set-top box.

Signed-off-by: Ferass El Hafidi <vitali64pmemail@protonmail.com>
Link: https://lore.kernel.org/r/20230507124109.31778-4-vitali64pmemail@protonmail.com
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
diff --git a/doc/board/amlogic/index.rst b/doc/board/amlogic/index.rst
index 66b581c..46f44bf 100644
--- a/doc/board/amlogic/index.rst
+++ b/doc/board/amlogic/index.rst
@@ -118,6 +118,7 @@
    sei610
    s400
    u200
+   videostrong-kii-pro
    wetek-core2
    wetek-hub
    wetek-play2