MAINTAINERS: Hand over skd maintainership

Since I do no longer have access to any STEC SSDs, hand over
maintainership of the skd driver to Damien who still has access to
STEC SSDs.

Cc: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.com>
Acked-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>