Sidebar navigation for supported boards is wonky: opens to show
all boards (making for lots of scrolling to see the sidebar) and
sidebar items aren't always clickable (as explained in the JIRA
issue).
Fix is to not use multiple toctree directives in boards.rst and
create intermediate architecture-specific supported board docs.
JIRA: INF-132
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
David B. Kinder