drm/amdgpu: Decode deferred error type in gfx aca bank parser

In the case of injecting uncorrected error with background workload,
the deferred error among uncorrected errors need to be specified
by checking the deferred and poison bits of status register.

v2: refine checking for deferred error
v2: log possiable DEs among CEs
v2: generate CPER records for DEs among UEs

Signed-off-by: Xiang Liu <xiang.liu@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>