drm/amdgpu/pm: add smc v2_1 printer in amdgpu_ucode_print_smc_hdr()

the smc v2_0 printer is not compatible with the smc v2_1 .
1. add smc v2_1 printer.
2. cleanup code

Signed-off-by: Kevin Wang <kevin1.wang@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>