Permit Lustre Client (only) modules DKMS RPM creation.

This patch is a follow on to the first set of patches for LU-1032
that only allowed for the creation of Lustre Server (zfs only)
modules DKMS RPM.

It also changes original behavior by allowing to dynamically
modify dkms.conf on-target. This particularly helps to change
configure and list of modules to be built/installed list, like
to configure with gss to build ptlrpc_gss.ko module when
krb5_devel is present instead to have it been a mandatory
required dependency.

Also implements feature of DKMS RPM creation from Makefile
(thanks to mjmac), now in 2 separate SRPM/RPM steps and for both
Client and Server versions.

Also use an auto-increment (Array[${#Array[@]}]=) operator in
dkms.conf modules declarations to help for future changes when
there will be a need to add/delete modules.

Change in lustre/utils Makefile has been required to allow
building of ptlrpc_gss module with --enable-gss and without the
need to specify --enable-utils which was causing an unexpected
zfs user-land dependency for DKMS Server build.

To satisfy lustre rpm requirement of a package providing
lustre-osd, provides has been added to DKMS Server RPM since
it does actually generate osd-zfs module.

Signed-off-by: Michael MacDonald <michael.macdonald@intel.com>
Signed-off-by: Bruno Faccini <bruno.faccini@intel.com>
Change-Id: I278d50307a17fe49a06392351890946b7dd3557a
Reviewed-on: http://review.whamcloud.com/12347


Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>