tests/amdgpu: add security test suite (v2)

This patch is to add a new test suite to store security tests.
In Raven+ asics, it will support TMZ (trust memory zone), and it is
page-based protection feature.

v2: remove tests/amdgpu/Makefile.am and update to
tests/amdgpu/meson.build

Acked-by: Huang Rui <ray.huang@amd.com>
Acked-by: Leo Liu <leo.liu@amd.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Aaron Liu <aaron.liu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>