MAINTAINERS: update nvme entry

The nvme emulated device development pace has increased recently.  Klaus
has offered to co-maintain, and since we have many new contributions
coming through, we're adding a repository to accumulate and test new
features.

Cc: Klaus Jensen <its@irrelevant.dk>
Acked-by: Klaus Jensen <k.jensen@samsung.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

MAINTAINERS

@@ -1856,10 +1856,12 @@ F: include/hw/virtio/virtio-mem.h
 
 nvme
 M: Keith Busch <kbusch@kernel.org>
+M: Klaus Jensen <its@irrelevant.dk>
 L: qemu-block@nongnu.org
 S: Supported
 F: hw/block/nvme*
 F: tests/qtest/nvme-test.c
+T: git git://git.infradead.org/qemu-nvme.git nvme-next
 
 megasas
 M: Hannes Reinecke <hare@suse.com>