drm/amdgpu/gfx12: properly reference EOP interrupts for userqs

Regardless of whether we disable kernel queues, we need
to take an extra reference to the pipe interrupts for
user queues to make sure they stay enabled in case we
disable them for kernel queues.

Reviewed-by: Sunil Khatri <sunil.khatri@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>