rpm: tell meson whether to use libssh or libssh2 explicitly

The %meson macro sets "--auto-features=enabled", thus any feature in the
RPM which has a "with_XXX" condition, needs to explicitly pass a
"-DXXX=state" arg to %meson to override the auto features setting.

The with_libssh and with_libssh2 conditions were not exposed to meson,
so if either was set disabled, then meson would fail the build if the
-devel packages were not found.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

libvirt.spec.in

@@ -1109,6 +1109,18 @@ exit 1
     %define arg_storage_iscsi_direct -Dstorage_iscsi_direct=disabled
 %endif
 
+%if %{with_libssh}
+    %define arg_libssh -Dlibssh=enabled
+%else
+    %define arg_libssh -Dlibssh=disabled
+%endif
+
+%if %{with_libssh2}
+    %define arg_libssh2 -Dlibssh2=enabled
+%else
+    %define arg_libssh2 -Dlibssh2=disabled
+%endif
+
 %define when  %(date +"%%F-%%T")
 %define where %(hostname)
 %define who   %{?packager}%{!?packager:Unknown}
@@ -1170,6 +1182,8 @@ export SOURCE_DATE_EPOCH=$(stat --printf='%Y' %{_specdir}/%{name}.spec)
            -Dfirewalld=enabled \
            %{?arg_firewalld_zone} \
            %{?arg_wireshark} \
+           %{?arg_libssh} \
+           %{?arg_libssh2} \
            -Dpm_utils=disabled \
            -Dnss=enabled \
            %{arg_packager} \