drm: Add missing break in the command line mode parsing code

As we parse the string given on the command line one char at a time, it
seems that we do want a break at every case.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_modes.c

@@ -1143,6 +1143,7 @@ bool drm_mode_parse_command_line_for_connector(const char *mode_option,
 				was_digit = false;
 			} else
 				goto done;
+			break;
 		case '0' ... '9':
 			was_digit = true;
 			break;