3878 blkdev needs to support DKIOCGMEDIAINFOEXT
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Approved by: Garrett D'Amore <garrett@damore.org>
Merge branch 'master' of github.com:illumos/illumos-gate