App: Combine the test threads together

This patch combines the test threads together to simplify
the codes and always build a test thread to output the EOT.

This also makes the output of EOT apply to non-test.

Change-Id: I4143dd9d59d663b432c599d36cddd26747d910af
Signed-off-by: Kevin Peng <kevin.peng@arm.com>
8 files changed