drm: Fix tabs vs. spaces

A set of 8 spaces has snuck in. Replace with a tab, and
toss in an extra newline while at it.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190326173401.7329-2-ville.syrjala@linux.intel.comReviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

include/drm/drm_connector.h

@@ -302,6 +302,7 @@ struct drm_display_info {
 	 * @width_mm: Physical width in mm.
 	 */
 	unsigned int width_mm;
+
 	/**
 	 * @height_mm: Physical height in mm.
 	 */