linux-imx

MAINTAINERS: Use @kernel.org address for Paul Burton

Switch to using my paulburton@kernel.org email address in order to avoid
subject mangling that's being imposed on my previous address.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: linux-kernel@vger.kernel.org