drm/amdgpu/discovery: add missing case for SMU 11.0.5

Was missed when converting the driver over to IP based
initialization.

Tested-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Guchun Chen <guchun.chen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>