Implement Negative Test for Platform Layer Functions (#1076)

* Implement Negative Tests for clPlatform Functions

This change introduces negative tests for clPlatform
functions as well as changes to the Harness to help with
other negative tests.

Signed-off-by: Chetankumar Mistry <chetan.mistry@arm.com>

* [SQUASH] Remove magic macro from Negative Platform Tests

This change removes the negative-testing macro and all
other changes related to its usage.

Signed-off-by: Chetankumar Mistry <chetan.mistry@arm.com>
7 files changed