Add NFS package mapping
Add NFS package mapping

In Fedora, the package is nfs-utils and in Debian the package is
'nfs-kernel-server'.

Change-Id: I34f793bb6eb43f749bf383a082e90371f8e28219

CSC-IT-Center-for-Science/diskimage-builder,JioCloud/diskimage-builder,switch-ch/diskimage-builder,citrix-openstack-build/diskimage-builder,eantyshev/diskimage-builder,openstack/diskimage-builder,rdo-management/diskimage-builder,takahashinobuyuki/diskimage-builder,openstack/diskimage-builder,eantyshev/diskimage-builder,NaohiroTamura/diskimage-builder,switch-ch/diskimage-builder,citrix-openstack-build/diskimage-builder,JioCloud/diskimage-builder,varunarya10/diskimage-builder,zioproto/diskimage-builder,CSC-IT-Center-for-Science/diskimage-builder,varunarya10/diskimage-builder,takahashinobuyuki/diskimage-builder,NaohiroTamura/diskimage-builder,zioproto/diskimage-builder,rdo-management/diskimage-builder