build/ops: rpm: make ceph-grafana-dashboards own its directories on SUSE

build/ops: rpm: make ceph-grafana-dashboards own its directories on SUSE

This is only required to get the spec file to build in the OpenSUSE
Build Service (OBS). Also, this change could potentially make the
package impossible to install together with grafana (if the latter
owns the same directories with different ownership/permissions).
Therefore, make the change specific to SUSE.

Fixes: http://tracker.ceph.com/issues/37485
Signed-off-by: Nathan Cutler <ncutler@suse.com>
Signed-off-by: Tim Serong <tserong@suse.com>