drm/plane: Fix typo in format_mod_supported documentation

Fix minor typo: "valdiate" -> "validate".
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Reviewed-by: Simon Ser <contact@emersion.fr>
Signed-off-by: Simon Ser <contact@emersion.fr>
Link: https://patchwork.freedesktop.org/patch/msgid/20211226112503.31771-3-jose.exposito89@gmail.com

include/drm/drm_plane.h

@@ -516,7 +516,7 @@ struct drm_plane_funcs {
 	 * This optional hook is used for the DRM to determine if the given
 	 * format/modifier combination is valid for the plane. This allows the
 	 * DRM to generate the correct format bitmask (which formats apply to
-	 * which modifier), and to valdiate modifiers at atomic_check time.
+	 * which modifier), and to validate modifiers at atomic_check time.
 	 *
 	 * If not present, then any modifier in the plane's modifier
 	 * list is allowed with any of the plane's formats.