build: Optionally use a VERSION file

Define the RTEMS version in the wscript.  Optionally use a VERSION file
to change the default values of the wscript.  Allow the command line
option --rtems-version to override __RTEMS_MAJOR__.  Remove support for
command line configurable options (--rtems-option).

Rename internal define RTEMS_VERSION_VC_KEY to
RTEMS_VERSION_CONTROL_KEY.

spec/build/cpukit/cpuopts.yml

@@ -7,12 +7,6 @@ guard: _RTEMS_SCORE_CPUOPTS_H
 include-headers: []
 install-path: ${BSP_INCLUDEDIR}/rtems/score
 links:
-- role: build-dependency
-  uid: optvermaj
-- role: build-dependency
-  uid: optvermin
-- role: build-dependency
-  uid: optverrev
 - role: build-dependency
   uid: optgcc
 - role: build-dependency

spec/build/cpukit/optvermaj.yml

@@ -1,13 +0,0 @@
-SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
-actions:
-- get-string-command-line: '6'
-- env-assign: null
-build-type: option
-copyrights:
-- Copyright (C) 2020 embedded brains GmbH & Co. KG
-default: []
-description: ''
-enabled-by: true
-links: []
-name: __RTEMS_MAJOR__
-type: build

spec/build/cpukit/optvermin.yml

@@ -1,13 +0,0 @@
-SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
-actions:
-- set-value: '0'
-- env-assign: null
-build-type: option
-copyrights:
-- Copyright (C) 2020 embedded brains GmbH & Co. KG
-default: []
-description: ''
-enabled-by: true
-links: []
-name: __RTEMS_MINOR__
-type: build

spec/build/cpukit/optverrev.yml

@@ -1,13 +0,0 @@
-SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
-actions:
-- set-value: '0'
-- env-assign: null
-build-type: option
-copyrights:
-- Copyright (C) 2020 embedded brains GmbH & Co. KG
-default: []
-description: ''
-enabled-by: true
-links: []
-name: __RTEMS_REVISION__
-type: build