spec/optconminor: Fix value type

The option for defining the console minor should be an integer, not a
boolean.

spec/build/bsps/optconminor.yml

@@ -1,15 +1,16 @@
 SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
 actions:
-- get-boolean: null
-- define-condition: null
+- get-integer: null
+- define: null
 build-type: option
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
-default: true
+default: 1
 default-by-variant: []
 description: |
   minor number of console device
 enabled-by: true
+format: '{}'
 links: []
 name: BSP_CONSOLE_MINOR
 type: build