drm/i915/display: add I915 conditional build to i9xx_plane.h

Add stubs for !I915.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/4ad1864c66adcf691906c37b554f640d04069fb2.1694514689.git.jani.nikula@intel.com

drivers/gpu/drm/i915/display/i9xx_plane.h

@@ -15,6 +15,7 @@ struct intel_initial_plane_config;
 struct intel_plane;
 struct intel_plane_state;
 
+#ifdef I915
 unsigned int i965_plane_max_stride(struct intel_plane *plane,
 				   u32 pixel_format, u64 modifier,
 				   unsigned int rotation);
@@ -25,4 +26,26 @@ intel_primary_plane_create(struct drm_i915_private *dev_priv, enum pipe pipe);
 
 void i9xx_get_initial_plane_config(struct intel_crtc *crtc,
 				   struct intel_initial_plane_config *plane_config);
+#else
+static inline unsigned int i965_plane_max_stride(struct intel_plane *plane,
+						 u32 pixel_format, u64 modifier,
+						 unsigned int rotation)
+{
+	return 0;
+}
+static inline int i9xx_check_plane_surface(struct intel_plane_state *plane_state)
+{
+	return 0;
+}
+static inline struct intel_plane *
+intel_primary_plane_create(struct drm_i915_private *dev_priv, int pipe)
+{
+	return NULL;
+}
+static inline void i9xx_get_initial_plane_config(struct intel_crtc *crtc,
+						 struct intel_initial_plane_config *plane_config)
+{
+}
+#endif
+
 #endif