drm/amdgpu: Fix SDMA RAS error reporting on Aldebaran

Fix the following issues with SDMA RAS error reporting:
1. Read the EDC_COUNTER2 register also to fetch error counts
   for all sub-blocks in SDMA.
2. SDMA RAS on Aldebaran suports single-bit uncorrectable errors
   only. So, report error count in UE count instead of CE count.

Signed-off-by: Mukul Joshi <mukul.joshi@amd.com>
Reviewed-By: John Clements <John.Clements@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>