drm/amdgpu: add missing CHIP_HAINAN in amdgpu_ucode_get_load_type

This caused a confusing error message, but there is functionally
no problem since the default method is DIRECT.

Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org