drm/amdgpu: bump smc firmware header version to v2 (v2)

This patch bumps smc firmware header version to v2 for storing soft pptable.

v2: fix the typo, and add prints for v2 header

Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>