drm/amdgpu: save rlcv/rlcp ucode version in amdgpu_gfx

cache rlcv/rlcvp ucode version info in amdgpu_gfx
structure

Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Likun Gao <Likun.Gao@amd.com>
Reviewed-by: Feifei Xu <Feifei.Xu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>