drm/amdkfd: fix dropped interrupt in kfd_int_process_v11

Shader wave interrupts were getting dropped in event_interrupt_wq_v11
if the PRIV bit was set to 1. This would often lead to a hang. Until
debugger logic is upstreamed, expand comment to stop early return.

Signed-off-by: Graham Sider <Graham.Sider@amd.com>
Reviewed-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>