Added scp SHOW SERIAL command

Fixed Ethernet formatting of open device names
Fixed serial generic naming to accomodate for the fact that an OS list of serial devices might not include devices which are already opened.

scp.c

@@ -217,6 +217,7 @@
 #include "sim_defs.h"
 #include "sim_rev.h"
 #include "sim_ether.h"
+#include "sim_serial.h"
 #include <signal.h>
 #include <ctype.h>
 #include <time.h>
@@ -697,6 +698,7 @@ static CTAB cmd_table[] = {
       "sh{ow} <dev> {arg,...}   show device parameters\n"
       "sh{ow} <unit> {arg,...}  show unit parameters\n"
       "sh{ow} ethernet          show ethernet devices\n"
+      "sh{ow} serial            show serial devices\n"
       "sh{ow} on                show on condition actions\n"  },
     { "DO", &do_cmd, 1,
       "do {-V} {-O} {-E} {-Q} <file> {arg,arg...}\b"
@@ -2040,6 +2042,7 @@ static SHTAB show_glob_tab[] = {
     { "THROTTLE", &sim_show_throt, 0 },
     { "ASYNCH", &sim_show_asynch, 0 },
     { "ETHERNET", &eth_show_devices, 0 },
+    { "SERIAL", &sim_show_serial, 0 },
     { "ON", &show_on, 0 },
     { NULL, NULL, 0 }
     };