drm/amdgpu: explicitly check for s0ix when evicting resources

This codepath should be running in both s0ix and s3, but only does
currently because s3 and s0ix are both set in the s0ix case.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>