drm/i915: Remove reference to struct drm_device.pdev

References to struct drm_device.pdev should not be used any longer as
the field will be moved into the struct's legacy section. Fix a rsp
comment.

v8:
	* fix commit message (Michael)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210429105101.25667-4-tzimmermann@suse.de

drivers/gpu/drm/i915/intel_runtime_pm.h

@@ -49,7 +49,7 @@ enum i915_drm_suspend_mode {
  */
 struct intel_runtime_pm {
 	atomic_t wakeref_count;
-	struct device *kdev; /* points to i915->drm.pdev->dev */
+	struct device *kdev; /* points to i915->drm.dev */
 	bool available;
 	bool suspended;
 	bool irqs_enabled;