hw/block/nvme: add NMIC enum value for Identify Namespace

Added Namespace Multi-path I/O and Namespace Sharing Capabilities (NMIC)
field to support shared namespace from controller(s).

This field is in Identify Namespace data structure in [30].

Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Tested-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>