drm/amdgpu: do not enable asic reset for raven2

The GPU reset function of raven2 is not maintained or tested, so it should be
very unstable.

Now the amdgpu_asic_reset function is added to amdgpu_pmops_suspend, which
causes the S3 test of raven2 to fail, so the asic_reset of raven2 is ignored
here.

Fixes: daf8de08

 ("drm/amdgpu: always reset the asic in suspend (v2)")
Signed-off-by: Chen Gong <curry.gong@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org