drm/amdgpu: Prefer RAS recovery for scheduler hang

Before scheduling a recovery due to scheduler/job hang, check if a RAS
error is detected. If so, choose RAS recovery to handle the situation. A
scheduler/job hang could be the side effect of a RAS error. In such
cases, it is required to go through the RAS error recovery process. A
RAS error recovery process in certains cases also could avoid a full
device device reset.

An error state is maintained in RAS context to detect the block
affected. Fatal Error state uses unused block id. Set the block id when
error is detected. If the interrupt handler detected a poison error,
it's not required to look for a fatal error. Skip fatal error checking
in such cases.

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