App: Remove the app codes from TF-M

This patch removes the app codes, they should have been in the
tf-m-tests repo. The app/ is only for testing, so it's naturaly
to move it to tf-m-tests.

Change-Id: I1230c6e734d1891558e75643f5c5c355d5ad9af1
Signed-off-by: Kevin Peng <kevin.peng@arm.com>
8 files changed