This patch changes the way XPT_GDEV_TYPE works for NVMe. The current ccb_getdev structure includes pointers to the NVMe Identify Controller and Namespace structures, but these are kernel virtual addresses which are not accessible from user space.

As an alternative, the patch removes these pointers from ccb_getdev and adds two new types to ccb_dev_advinfo to retrieve the Identify Controller (CDAI_TYPE_NVME_CNTRL) and Namespace (CDAI_TYPE_NVME_NS) data structures.