u_boot_pylib: Support a fatal level in tout

It is convenient to be able to print a message and exit. Add a new
'fatal' level to support this.

Update some assumptions about the level, so that the tools continue to
work as now.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/control.py b/tools/binman/control.py
index 81f61e3..1946656 100644
--- a/tools/binman/control.py
+++ b/tools/binman/control.py
@@ -777,7 +777,7 @@
 
     if args.cmd in ['ls', 'extract', 'replace', 'tool', 'sign']:
         try:
-            tout.init(args.verbosity)
+            tout.init(args.verbosity + 1)
             if args.cmd == 'replace':
                 tools.prepare_output_dir(args.outdir, args.preserve)
             else:
@@ -835,9 +835,9 @@
         args.indir.append(board_pathname)
 
     try:
-        tout.init(args.verbosity)
+        tout.init(args.verbosity + 1)
         elf.debug = args.debug
-        cbfs_util.VERBOSE = args.verbosity > 2
+        cbfs_util.VERBOSE = args.verbosity > tout.NOTICE
         state.use_fake_dtb = args.fake_dtb
 
         # Normally we replace the 'u-boot' etype with 'u-boot-expanded', etc.