drm/i915: Provide the perf pmu.module

Rather than manually implement our own module reference counting for perf
pmu events, finally realise that there is a module parameter to struct
pmu for this very purpose.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200716094643.31410-1-chris@chris-wilson.co.uk


Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>