scmi_perf: Fixing perf protocol ops unit test build

The SCMI-perf protocol ops default unit test target is build with
BUILD_HAS_SCMI_PERF_FAST_CHANNELS flag, which was incorrectly
introduced, has now been removed.

The two unit tests for checking incorrect message id which was not
being compiled before for default target are modified accordingly.

Signed-off-by: Md Golam Tanvir Zim <mdgolamtanvir.zim@arm.com>
Change-Id: Ia18b4c7ffa8bfc0d70d2a55e9d5a7358366d00a5