LU-13903 build: make lustre-devel buildable for Linux client

LU-13903 build: make lustre-devel buildable for Linux client

Recently a new lustre-devel rpm was created which always has a
dependency on the kernel detected by the kmod macros. This doesn't
work in the case of running a custom Linux kernel. Addreess this
by not making use of the kmod macros when only building the Lustre
utilies i.e configure --disable-modules.

Test-Parameters: trivial
Fixes: 16af4e5ed634 ("LU-9215 build: Re-add the lustre-devel package")
Signed-off-by: James Simmons <jsimmons@infradead.org>
Change-Id: I324fbaa0f5b03e2095b493f3d8e00b74ca64298a
Reviewed-on: https://review.whamcloud.com/41188
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Neil Brown <neilb@suse.de>
Reviewed-by: Oleg Drokin <green@whamcloud.com>