drm/amdgpu: reserve fb according to return value from vbios

Query reserved tmr size through atom firmwareinfo for Sienna_Cichlid and onwards
for all the use cases (IP discovery/G6 memory
training/profiling/diagnostic data.etc), otherwise, fallback to legacy
approach to check and reserve tmr block for ip discovery data and G6
memory training data respectively

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