Add set_dsp_flt for IC7000 -- any other Icom rigs can use this?

https://github.com/Hamlib/Hamlib/issues/521

rigs/icom/icom.c

@@ -1488,8 +1488,6 @@ pbwidth_t icom_get_dsp_flt(RIG *rig, rmode_t mode)
     return 0;
 }
 
-#ifdef XXREMOVEDXX
-// not referenced anywhere
 int icom_set_dsp_flt(RIG *rig, rmode_t mode, pbwidth_t width)
 {
     int retval, rfstatus;
@@ -1573,7 +1571,6 @@ int icom_set_dsp_flt(RIG *rig, rmode_t mode, pbwidth_t width)
 
     return RIG_OK;
 }
-#endif
 
 /*
  * icom_set_mode_with_data
@@ -1762,20 +1759,15 @@ int icom_set_mode(RIG *rig, vfo_t vfo, rmode_t mode, pbwidth_t width)
         return -RIG_ERJCTED;
     }
 
-#if 0
-
-    /* Tentative DSP filter setting ($1A$03), but not supported by every rig,
+    /* DSP filter setting ($1A$03), but not supported by every rig,
      * and some models like IC910/Omni VI Plus have a different meaning for
      * this subcommand
      */
-    if ((rig->caps->rig_model != RIG_MODEL_IC910) &&
-            (rig->caps->rig_model != RIG_MODEL_OMNIVIP))
+    if (rig->caps->rig_model == RIG_MODEL_IC7000)
     {
         icom_set_dsp_flt(rig, mode, width);
     }
 
-#endif
-
     return RIG_OK;
 }
 

rigs/icom/icom.h

@@ -30,7 +30,7 @@
 #include <sys/time.h>
 #endif
 
-#define BACKEND_VER "20210212"
+#define BACKEND_VER "20210217"
 
 /*
  * defines used by comp_cal_str in rig.c