PM / devfreq: Fix build issues with devfreq disabled

PM / devfreq: Fix build issues with devfreq disabled

The existing no-op shims for when PM_DEVFREQ (or an individual governor)
only do half the job.  The governor specific config/tuning structs need
to be available to avoid compile errors in drivers using devfreq.

Fixes: 6563f60f14cb ("drm/msm/gpu: Add devfreq tuning debugfs")
Signed-off-by: Rob Clark <[email protected]>
Acked-by: MyungJoo Ham <[email protected]>
Acked-by: Chanwoo Choi <[email protected]>
Patchwork: https://patchwork.freedesktop.org/patch/519801/
Link: https://lore.kernel.org/r/[email protected]