Add sim time duration comment.

applications/lofar2/designs/lofar2_unb2b_sdp_station/revisions/disturb2_unb2b_sdp_station_full_wg/tb_disturb2_unb2b_sdp_station_full_wg.vhd

@@ -57,6 +57,7 @@
 --     index signals to have a more compact view of the relevant indices.
 --   . If c_subband_phase = 0.0 then beamlet_arr2_re entries are 0.
 --   . manually add top level generics/constants to wave window.
+--   Takes about 1h.
 --
 -- Remark: TB is based on tb_lofar2_unb2c_sdp_station_bf.
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