drm/amdgpu: only uncorrectable error needs gpu reset

we only read error information for correctable error in interrupt
handler, gpu reset is unnecessary since there is no data lost
in correctable error

Signed-off-by: Tao Zhou <tao.zhou1@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>