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 <[e-mail]>
Acked-by: MyungJoo Ham <[e-mail]>
Acked-by: Chanwoo Choi <[e-mail]>
Patchwork: https://patchwork.freedesktop.org/patch/519801/
Link: https://lore.kernel.org/r/[e-mail]

include/linux/devfreq.h

···
 struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node);
 struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
 				const char *phandle_name, int index);
+#endif /* CONFIG_PM_DEVFREQ */
 
-#if IS_ENABLED(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)
 /**
  * struct devfreq_simple_ondemand_data - ``void *data`` fed to struct devfreq
  *	and devfreq_add_device
···
 	unsigned int upthreshold;
 	unsigned int downdifferential;
 };
-#endif
 
-#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
 enum devfreq_parent_dev_type {
 	DEVFREQ_PARENT_DEV,
 	CPUFREQ_PARENT_DEV,
···
 	struct notifier_block nb;
 	struct list_head cpu_data_list;
 };
-#endif
 
-#else /* !CONFIG_PM_DEVFREQ */
+#if !defined(CONFIG_PM_DEVFREQ)
 static inline struct devfreq *devfreq_add_device(struct device *dev,
 					struct devfreq_dev_profile *profile,
 					const char *governor_name,