drm/amdgpu: use psp_execute_load_ip_fw instead

Replace the old ones with psp_execute_load_ip_fw.

Suggested-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Lang Yu <Lang.Yu@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>