drm/i915: Use intel_tile_height() instead of re-implementing

intel_tile_dims() computes tile height using size and width, when there
is already a function to do just that - intel_tile_height()

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-2-imre.deak@intel.com

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

@@ -1998,7 +1998,7 @@ static void intel_tile_dims(const struct drm_framebuffer *fb, int color_plane,
 	unsigned int cpp = fb->format->cpp[color_plane];
 
 	*tile_width = tile_width_bytes / cpp;
-	*tile_height = intel_tile_size(to_i915(fb->dev)) / tile_width_bytes;
+	*tile_height = intel_tile_height(fb, color_plane);
 }
 
 unsigned int