drm/amdgpu: Enable RAS feature by default for APU

Enable RAS feature by default for aqua vanjaram on apu
platform.

Signed-off-by: Stanley.Yang <Stanley.Yang@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>