drm/amdgpu: add VCN4_0_3 firmware

Add VCN4_0_3 firmware.

v2: fix fw name (Alex)

Signed-off-by: James Zhu <James.Zhu@amd.com>
Reviewed-by: Leo Liu <leo.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>