drm/i915: drop intel_display.h include from intel_display_power.h

Use forward declarations instead.

Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211116171434.20516-5-jani.nikula@intel.com

drivers/gpu/drm/i915/display/intel_display_power.h

@@ -6,10 +6,11 @@
 #ifndef __INTEL_DISPLAY_POWER_H__
 #define __INTEL_DISPLAY_POWER_H__
 
-#include "intel_display.h"
 #include "intel_runtime_pm.h"
 #include "i915_reg.h"
 
+enum dpio_channel;
+enum dpio_phy;
 struct drm_i915_private;
 struct i915_power_well;
 struct intel_encoder;