given descriptors, use Capsicum sandboxing for hastd in primary and secondary
modes. Allow for DIOCGDELETE and DIOCGFLUSH ioctls on provider descriptor and
for G_GATE_CMD_MODIFY, G_GATE_CMD_START, G_GATE_CMD_DONE and G_GATE_CMD_DESTROY
on GEOM Gate descriptor.
Sponsored by: The FreeBSD Foundation