MAINTAINERS: add CLANG/LLVM BUILD SUPPORT info

Add keyword support so that our mailing list gets cc'ed for clang/llvm
patches.  We're pretty active on our mailing list so far as code review.
There are numerous Googlers like myself that are paid to support
building the Linux kernel with Clang and LLVM.

Link: http://lkml.kernel.org/r/20190620001907.255803-1-ndesaulniers@google.comSigned-off-by: NNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: NNathan Chancellor <natechancellor@gmail.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS

@@ -3942,6 +3942,14 @@ M:	Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
 S:	Maintained
 F:	.clang-format
 
+CLANG/LLVM BUILD SUPPORT
+L:	clang-built-linux@googlegroups.com
+W:	https://clangbuiltlinux.github.io/
+B:	https://github.com/ClangBuiltLinux/linux/issues
+C:	irc://chat.freenode.net/clangbuiltlinux
+S:	Supported
+K:	\b(?i:clang|llvm)\b
+
 CLEANCACHE API
 M:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
 L:	linux-kernel@vger.kernel.org