If we don't enable audio runtime PM, the audio driver won't release
its reference, the refcount won't ever become zero, so we will never
actually runtime suspend. So move this code from pm_rpm.c to
igt_aux.c, so kms_flip - and any other IGT test case using RPM - can
benefit from it.
Previously, if you ran pm_rpm before running the other tests - or if
you just didn't have snd_hda_intel loaded - you wouldn't notice this
bug.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78893
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>