drm/i915: Remove repeated declaration

struct drm_i915_private, struct intel_crtc_state and
struct intel_crtc is declared twice.
Remove the duplicate.
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210326012527.875026-1-wanjiabing@vivo.com

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

@@ -11,7 +11,6 @@
 enum pipe;
 struct drm_encoder;
 struct drm_i915_private;
-struct drm_i915_private;
 
 bool intel_crt_port_enabled(struct drm_i915_private *dev_priv,
 			    i915_reg_t adpa_reg, enum pipe *pipe);

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

@@ -48,7 +48,6 @@ struct i915_ggtt_view;
 struct intel_atomic_state;
 struct intel_crtc;
 struct intel_crtc_state;
-struct intel_crtc_state;
 struct intel_digital_port;
 struct intel_dp;
 struct intel_encoder;

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

@@ -15,7 +15,6 @@ struct intel_crtc;
 struct intel_crtc_state;
 struct intel_dp;
 struct intel_encoder;
-struct intel_crtc;
 
 bool intel_vrr_is_capable(struct drm_connector *connector);
 void intel_vrr_check_modeset(struct intel_atomic_state *state);