buildman: Fetch 12.2.0 toolchains by default

Update the toolchain list to be first 12.2.0 and second 11.1.0 and
that's it.

Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

tools/buildman/toolchain.py

@@ -498,7 +498,7 @@ class Toolchains:
         if arch == 'aarch64':
             arch = 'arm64'
         base = 'https://www.kernel.org/pub/tools/crosstool/files/bin'
-        versions = ['11.1.0', '9.2.0', '7.3.0', '6.4.0', '4.9.4']
+        versions = ['12.2.0', '11.1.0']
         links = []
         for version in versions:
             url = '%s/%s/%s/' % (base, arch, version)