Documentation/process: Add embargoed HW contact for LLVM

Should the need for toolchain mitigations ever be necessary, add a group
for toolchain ambassadors.

Add Nick Desaulniers as LLVM's ambassador for the embargoed hardware
issues process.
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20220711181101.1559558-1-ndesaulniers@google.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/process/embargoed-hardware-issues.rst

@@ -264,6 +264,9 @@ an involved disclosed party. The current ambassadors list:
 
   Amazon
   Google	Kees Cook <keescook@chromium.org>
+
+  GCC
+  LLVM		Nick Desaulniers <ndesaulniers@google.com>
   ============= ========================================================
 
 If you want your organization to be added to the ambassadors list, please