tests/amdgpu: Add VCN test support for Biege Goby

Added Beige Goby chip id in vcn test.

Signed-off-by: Guchun Chen <guchun.chen@amd.com>
Reviewed-By: Veerabadhran Gopalakrishnan <Veerabadhran.gopalakrishnan@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Leo Liu <leo.liu@amd.com>