buildman: Use -D for --debug

Change -D to mean --debug for consistency with other tools. This is not a
commonly used option, so the impact should be minimal.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/buildman/buildman.rst

@@ -1062,9 +1062,9 @@ same as 'am335x_evm_usbspl'/
 
 The -K option uses the u-boot.cfg, spl/u-boot-spl.cfg and tpl/u-boot-tpl.cfg
 files which are produced by a build. If all you want is to check the
-configuration you can in fact avoid doing a full build, using -D. This tells
-buildman to configuration U-Boot and create the .cfg files, but not actually
-build the source. This is 5-10 times faster than doing a full build.
+configuration you can in fact avoid doing a full build, using --config-only.
+This tells buildman to configuration U-Boot and create the .cfg files, but not
+actually build the source. This is 5-10 times faster than doing a full build.
 
 By default buildman considers the follow two configuration methods
 equivalent::

tools/buildman/cmdline.py

@@ -38,13 +38,13 @@ def add_upto_m(parser):
     parser.add_argument('-C', '--force-reconfig', dest='force_reconfig',
           action='store_true', default=False,
           help='Reconfigure for every commit (disable incremental build)')
+    parser.add_argument('--config-only', action='store_true',
+                        default=False,
+                        help="Don't build, just configure each commit")
     parser.add_argument('-d', '--detail', dest='show_detail',
           action='store_true', default=False,
           help='Show detailed size delta for each board in the -S summary')
-    parser.add_argument('-D', '--config-only', action='store_true',
-                        default=False,
-          help="Don't build, just configure each commit")
-    parser.add_argument('--debug', action='store_true',
+    parser.add_argument('-D', '--debug', action='store_true',
         help='Enabling debugging (provides a full traceback on error)')
     parser.add_argument('-e', '--show_errors', action='store_true',
           default=False, help='Show errors and warnings')