Load records in st.cmd

Until now, records were only being loaded by local changes in st.cmd file.
This commit adds channels.substitutions and channels.template to makefile,
and loads its expansion in the st.cmd.

cmds/st.cmd

@@ -27,6 +27,7 @@ dbLoadRecords("$(rmm_DB)/topology.template", "P=$(P), R=$(R), PORT=RMM, RING=0,
 dbLoadRecords("$(vmmTbl_DB)/vmm_tbl.db", "P=$(P), R=NDet-VMM-001:, PORT=RMM, RING=0, NODE=0, ADDR=0, TIMEOUT=1")
 dbLoadRecords("$(vmmTbl_DB)/hybrid.db", "P=$(P), R=NDet-VMM-001:, PORT=RMM, HYB=0, ADDR=0, TIMEOUT=1")
 dbLoadRecords("$(vmmTbl_DB)/hybrid.db", "P=$(P), R=NDet-VMM-001:, PORT=RMM, HYB=1, ADDR=0, TIMEOUT=1")
+dbLoadRecords("channels.db", "P=$(P), R=NDet-VMM-001:, PORT=RMM, ADDR=0, TIMEOUT=1")
 
 iocInit()