dev-manual, ref-manual: Updated available names for TEST_TARGET

dev-manual, ref-manual: Updated available names for TEST_TARGET

The documentation of available names for TEST_TARGET has been
updated to match the convention of using the class names of
controllers.

This commit was modified some to make it work.  Fixed some
formatting errors and isolated and changed missed instances.

(From yocto-docs rev: 1bec1dc38cdd1746ce6dd539f9c3e5665d12ab8e)

Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>