spec: Add support for libssh2 transport

Libssh2 transport support was enabled lately but the spec file wasn't
updated to take this into account. This caused libvirt to be built
without libssh2 support in Red Hat based OSes.

libvirt.spec.in

@@ -108,6 +108,7 @@
 %define with_systemd       0%{!?_without_systemd:0}
 %define with_numad         0%{!?_without_numad:0}
 %define with_firewalld     0%{!?_without_firewalld:0}
+%define with_libssh2_transport 0%{!?_without_libssh2_transport:0}
 
 # Non-server/HV driver defaults which are always enabled
 %define with_python        0%{!?_without_python:1}
@@ -229,6 +230,11 @@
 %endif
 %endif
 
+# Enable libssh2 transport for new enough distros
+%if 0%{?fedora} >= 17 || 0%{?rhel} >= 6
+%define with_libssh2_transport 0%{!?_without_libssh2_transport:1}
+%endif
+
 # Disable some drivers when building without libvirt daemon.
 # The logic is the same as in configure.ac
 %if ! %{with_libvirtd}
@@ -491,9 +497,13 @@ BuildRequires: numactl-devel
 %if %{with_capng}
 BuildRequires: libcap-ng-devel >= 0.5.0
 %endif
-%if %{with_phyp}
+%if %{with_phyp} || %{with_libssh2_transport}
+%if %{with_libssh2_transport}
+BuildRequires: libssh2-devel >= 1.3.0
+%else
 BuildRequires: libssh2-devel
 %endif
+%endif
 
 %if %{with_netcf}
 %if 0%{?fedora} >= 18 || 0%{?rhel} >= 7