Add a new ioctl for the larger params struct that includes the label.

We need to make the find_veriexec_file() function available publicly, so
rename it to mac_veriexec_metadata_find_file_info() and make it non-static.

Bump the version of the veriexec device interface so user space will know
the labelized version of fingerprint loading is available.

Approved by: sjg
Obtained from: Juniper Networks, Inc.
Differential Revision: https://reviews.freebsd.org/D20295