drm/i915/intel_fb: Unexport intel_fb_check_stride()

After the previous patch we can unexport intel_fb_check_stride(), which
isn't needed by intel_display.c.
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210325214808.2071517-12-imre.deak@intel.com

drivers/gpu/drm/i915/display/intel_fb.c

@@ -824,7 +824,7 @@ void intel_fill_fb_ggtt_view(struct i915_ggtt_view *view,
 	}
 }
 
-int intel_plane_check_stride(const struct intel_plane_state *plane_state)
+static int intel_plane_check_stride(const struct intel_plane_state *plane_state)
 {
 	struct intel_plane *plane = to_intel_plane(plane_state->uapi.plane);
 	const struct drm_framebuffer *fb = plane_state->hw.fb;

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

@@ -28,8 +28,6 @@ int main_to_ccs_plane(const struct drm_framebuffer *fb, int main_plane);
 int skl_ccs_to_main_plane(const struct drm_framebuffer *fb, int ccs_plane);
 int skl_main_to_aux_plane(const struct drm_framebuffer *fb, int main_plane);
 
-int intel_plane_check_stride(const struct intel_plane_state *plane_state);
-
 unsigned int intel_tile_size(const struct drm_i915_private *dev_priv);
 unsigned int intel_tile_height(const struct drm_framebuffer *fb, int color_plane);
 unsigned int intel_tile_row_size(const struct drm_framebuffer *fb, int color_plane);