Add NVMe command building functions for the four NVMe
reservation opcodes: nvme_ns_resv_report_cmd(),
nvme_ns_resv_register_cmd(), nvme_ns_resv_acquire_cmd() and
nvme_ns_resv_release_cmd().

Add enumerated types for the various NVMe reservation
subcommand actions (acquire, register, release), reservation
types, and Change Persist Through Power Loss State values.

Add struct nvme_resv_acq_data and struct nvme_resv_reg_data,
the data payloads for reservation Acquire and Register.

Add a new NVMe Format NVM command building function,
nvme_admin_format_cmd(), and an enumeration for the Secure
Erase Setting parameter for format.

Add nvme_admin_get_feature_cmd() and
nvme_admin_set_feature_cmd() functions to fill a struct
nvme_command for Get Features / Set Features.

Add macros for bitfields in the ctratt and mic dwords of the
NVMe Identify Controller data structure.

Add a prototype for nvme_hostid_sbuf().

Stop byte swapping the hostid fields in
nvme_resv_status_swapbytes() and
nvme_resv_status_ext_swapbytes(), and document the fields as
little endian.  The hostid is an opaque 8 or 16 byte value;
keep it in the byte order the device returns it in instead of
interpreting it at this level.

Widen the nvme_ctrlr_cmd_get_feature() and
nvme_ctrlr_cmd_set_feature() prototypes as described below.

Add nvme_hostid_sbuf(), which formats an 8 or 16 byte hostid
(from the Get Features hostid feature, in the little-endian
byte order the device returns it in) into an sbuf as an
integer value in base 16, most significant byte first.

Decode the now little-endian hostid fields explicitly when
printing, and zero pad the printed 64-bit values.  Previously
the extended hostid printed in a different byte order on big
and little endian machines, and without zero padding between
the two halves.

Refactor nvme_ctrlr_cmd_get_feature() and
nvme_ctrlr_cmd_set_feature() to use the new command building
functions from nvme.h and accept a namespace ID parameter.

Refactor nvme_ctrlr_cmd_set_feature() to also accept the sv
(save) parameter to persist a feature value across reset.

Update the temperature threshold, autonomous power state
transition and host memory buffer callers for the new
nvme_ctrlr_cmd_get_feature() and nvme_ctrlr_cmd_set_feature()
arguments.