LU-2675 mdd: remove dead code

LU-2675 mdd: remove dead code

Remove the declarations of several undefined mdd functions. Remove
several unused functions. Remove the file mdd_lov.c.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: Ife0d13ee414bd43c42389d9e58d9dd97344cb33c
Reviewed-on: http://review.whamcloud.com/8548
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>