drm/i915: Rename i915_opregion.c to intel_opregion.c

It's part of the generic Intel driver infrastructure so rename it in
prepreparation for using it for VBT.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 04aada0..980061f 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1054,18 +1054,18 @@
 extern int i915_restore_state(struct drm_device *dev);
 
 #ifdef CONFIG_ACPI
-/* i915_opregion.c */
+/* intel_opregion.c */
 extern int intel_opregion_init(struct drm_device *dev, int resume);
 extern void intel_opregion_free(struct drm_device *dev, int suspend);
-extern void opregion_asle_intr(struct drm_device *dev);
-extern void ironlake_opregion_gse_intr(struct drm_device *dev);
-extern void opregion_enable_asle(struct drm_device *dev);
+extern void intel_opregion_asle_intr(struct drm_device *dev);
+extern void intel_opregion_gse_intr(struct drm_device *dev);
+extern void intel_opregion_enable_asle(struct drm_device *dev);
 #else
 static inline int intel_opregion_init(struct drm_device *dev, int resume) { return 0; }
 static inline void intel_opregion_free(struct drm_device *dev, int suspend) { return; }
-static inline void opregion_asle_intr(struct drm_device *dev) { return; }
-static inline void ironlake_opregion_gse_intr(struct drm_device *dev) { return; }
-static inline void opregion_enable_asle(struct drm_device *dev) { return; }
+static inline void intel_opregion_asle_intr(struct drm_device *dev) { return; }
+static inline void intel_opregion_gse_intr(struct drm_device *dev) { return; }
+static inline void intel_opregion_enable_asle(struct drm_device *dev) { return; }
 #endif
 
 /* modesetting */