Add SCSI passthrough to CTL

[Bhimanshu Kumar]

*Introduction : *CTL is the FreeBSD SCSI target layer. There are various
SCSI commands, but it's usually used for block-level access. This projects
focuses on making CTL capable of providing physical optical drive as a
whole to the initiator machine
Link : https://github.com/bhimanshu1997/freebsd

Report:
1. code has been added in ctld (kernel.c) which will convert the address of
device (provided in modified ctl.conf) to the actual device (for eg
"/dev/da0") and pass on the lun to CTL via ioctl


next week plan :
1. Test the above thing, if it works with the code added in ctld
2. If did not work then , will add that device address conversion code to
CTL