drm/amdgpu: update psp gfx i/f to support dynamic GECC

psp_gfx_uresp_bootcfg is used to inform driver
bootcfg settings maintained by tOS

Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: John Clements <john.clements@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>