drm/i915: wrap up gt powersave enabling functions

... instead of calling each one for each generation indiviudally.

Notice that we've already managed to be inconsistent, the resume path
is missing an IS_VLV check. As a nice benefit we can mark all the
platform specific enable/disable functions as static and hide them in
intel_pm.c

Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 5290e9d..cc1573b 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -425,9 +425,6 @@
 extern void intel_crtc_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
 				    u16 *blue, int regno);
 extern void intel_enable_clock_gating(struct drm_device *dev);
-extern void ironlake_disable_rc6(struct drm_device *dev);
-extern void ironlake_enable_drps(struct drm_device *dev);
-extern void ironlake_disable_drps(struct drm_device *dev);
 
 extern int intel_pin_and_fence_fb_obj(struct drm_device *dev,
 				      struct drm_i915_gem_object *obj,
@@ -494,10 +491,8 @@
 extern void intel_gpu_ips_init(struct drm_i915_private *dev_priv);
 extern void intel_gpu_ips_teardown(void);
 
-extern void gen6_enable_rps(struct drm_i915_private *dev_priv);
-extern void gen6_update_ring_freq(struct drm_i915_private *dev_priv);
-extern void gen6_disable_rps(struct drm_device *dev);
-extern void intel_init_emon(struct drm_device *dev);
+extern void intel_enable_gt_powersave(struct drm_device *dev);
+extern void intel_disable_gt_powersave(struct drm_device *dev);
 
 extern void intel_ddi_dpms(struct drm_encoder *encoder, int mode);
 extern void intel_ddi_mode_set(struct drm_encoder *encoder,