Drop installation-time dependencies on dracut and kmod

rdma-core provides a plugin for dracut, but does not "use" dracut.

It seems that the dependencies on dracut and kmod were added because
of directory ownership
(https://bugzilla.redhat.com/show_bug.cgi?id=1404043#c8). Let's co-own
the directories instead. Pulling in such a big package as dracut along
with dependencies just for the directory is not very nice.

Dracut by itself is 1MB, and pulls in bash, coreutils, grep (which
means also libpcre), procps-ng, systemd, and a bunch of libraries.

rdma-core.spec

@@ -54,7 +54,7 @@ BuildRequires: python-docutils
 BuildRequires: perl-generators
 %endif
 
-Requires: dracut, kmod, pciutils
+Requires: pciutils
 # Red Hat/Fedora previously shipped redhat/ as a stand-alone
 # package called 'rdma', which we're supplanting here.
 Provides: rdma = %{version}-%{release}
@@ -390,11 +390,14 @@ rm -f %{buildroot}/%{_sbindir}/srp_daemon.sh
 %config(noreplace) %{_sysconfdir}/rdma/rdma.conf
 %config(noreplace) %{_sysconfdir}/rdma/sriov-vfs
 %config(noreplace) %{_sysconfdir}/udev/rules.d/*
+%dir %{_sysconfdir}/modprobe.d
 %config(noreplace) %{_sysconfdir}/modprobe.d/mlx4.conf
 %config(noreplace) %{_sysconfdir}/modprobe.d/truescale.conf
 %{_unitdir}/rdma-hw.target
 %{_unitdir}/rdma-load-modules@.service
 %{_unitdir}/rdma.service
+%dir %{dracutlibdir}
+%dir %{dracutlibdir}/modules.d
 %dir %{dracutlibdir}/modules.d/05rdma
 %{dracutlibdir}/modules.d/05rdma/module-setup.sh
 %dir %{_udevrulesdir}
@@ -406,6 +409,7 @@ rm -f %{buildroot}/%{_sbindir}/srp_daemon.sh
 %{_udevrulesdir}/90-rdma-ulp-modules.rules
 %{_udevrulesdir}/90-rdma-umad.rules
 %{_udevrulesdir}/98-rdma.rules
+%dir %{sysmodprobedir}
 %{sysmodprobedir}/libmlx4.conf
 %{_libexecdir}/rdma-init-kernel
 %{_libexecdir}/rdma-set-sriov-vf