MAINTAINERS: extend firmware_class maintainer list

I've been reviewing changes proactively, and plan on doing
more of this work. I'm doing this early as I should be getting
e-mailed about proposed changes.
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MAINTAINERS

@@ -4850,6 +4850,7 @@ F:	tools/firewire/
 
 FIRMWARE LOADER (request_firmware)
 M:	Ming Lei <ming.lei@canonical.com>
+M:	Luis R. Rodriguez <mcgrof@kernel.org>
 L:	linux-kernel@vger.kernel.org
 S:	Maintained
 F:	Documentation/firmware_class/