drm/amdgpu: fix for suspend/resume sequence under sriov

- clear kiq ring after suspend/resume under sriov to aviod kiq ring
test failure
- update irq after resume to fix kiq interrput loss

Signed-off-by: Victor Zhao <Victor.Zhao@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>