sb: Align the version processing with rtems-tools.

- Use the same VERSION file format as rtems-tools so a common release
  generation can be used.

- The version.py is almost the same as rtems-tools. There are some
  minor differences, one is the RTEMS version is present in this
  file while rtems-tool uses config/rtems-release.ini.

Updates #3822

source-builder/sb/check.py

@@ -264,7 +264,7 @@ def run():
     import sys
     try:
         _opts = options.load(args = sys.argv, logfile = False)
-        log.notice('RTEMS Source Builder - Check, %s' % (version.str()))
+        log.notice('RTEMS Source Builder - Check, %s' % (version.string()))
 
         orphans = _opts.parse_args('--check-orphans', error = False, extra = False)
         if orphans: