ndctl: release v71

This release incorporates functionality up to the 5.10 kernel.

Highlights include support for the new device-dax subdivision
functionality added in Linux in v5.10, including ways to create smaller
devdax devices using daxctl/libdaxctl, as well as creating, listing, and
restoring from a config dump, 'mappings' on these devices. Other updates
include several static analysis fixups, reworking the license
identification scheme for different sub-components, and a fix for the
reconfigure-in-place workflow which tries to retain device names.

Commands:
  daxctl-create-device: new command
  daxctl-destroy-device: new command
  daxctl-enable-device: new command
  daxctl-disable-device: new command
  daxctl-reconfigure-device: allow resizing devices
  ndctl-create-namespace: improve reconfigure in-place

Tests:
  daxctl-create.sh: new test for device-dax subdivision

APIs:
  daxctl_dev_get_align
  daxctl_dev_set_align
  daxctl_dev_set_mapping
  daxctl_dev_set_size
  daxctl_mapping_get_end
  daxctl_mapping_get_first
  daxctl_mapping_get_next
  daxctl_mapping_get_offset
  daxctl_mapping_get_size
  daxctl_mapping_get_start
  daxctl_region_create_dev
  daxctl_region_destroy_dev