drm/amdgpu: move amdgpu_gmc_tmz_set after ip_version populated

To enable TMZ feature based on IP version needs adev->ip_version
populated but its empty. Move amdgpu_gmc_tmz_set to a place where
ip_version is populated.

Signed-off-by: Sunil Khatri <sunil.khatri@amd.com>
Reviewed-by: Alexander Deucher <Alexander.Deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>