drm/amdgpu: Rearm IRQ in Vega10 SR-IOV if IRQ lost

In Multi-VFs stress test, sometimes we see IRQ lost when running
benchmark, just rearm it.

Signed-off-by: Trigger Huang <Trigger.Huang@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>