Revert "hmp: Disable chardev-add and chardev-remove"

This reverts commit 8a14952c9d.

hmp-commands.hx

@@ -1522,38 +1522,37 @@ passed since 1970, i.e. unix epoch.
 @end table
 ETEXI
 
-HXCOMM Disabled for now, because it isn't built on top of QMP's chardev-add
-HXCOMM     {
-HXCOMM         .name       = "chardev-add",
-HXCOMM         .args_type  = "args:s",
-HXCOMM         .params     = "args",
-HXCOMM         .help       = "add chardev",
-HXCOMM         .mhandler.cmd = hmp_chardev_add,
-HXCOMM     },
-HXCOMM
-HXCOMM STEXI
-HXCOMM @item chardev_add args
-HXCOMM @findex chardev_add
-HXCOMM
-HXCOMM chardev_add accepts the same parameters as the -chardev command line switch.
-HXCOMM
-HXCOMM ETEXI
-HXCOMM
-HXCOMM     {
-HXCOMM         .name       = "chardev-remove",
-HXCOMM         .args_type  = "id:s",
-HXCOMM         .params     = "id",
-HXCOMM         .help       = "remove chardev",
-HXCOMM         .mhandler.cmd = hmp_chardev_remove,
-HXCOMM     },
-HXCOMM
-HXCOMM STEXI
-HXCOMM @item chardev_remove id
-HXCOMM @findex chardev_remove
-HXCOMM
-HXCOMM Removes the chardev @var{id}.
-HXCOMM
-HXCOMM ETEXI
+    {
+        .name       = "chardev-add",
+        .args_type  = "args:s",
+        .params     = "args",
+        .help       = "add chardev",
+        .mhandler.cmd = hmp_chardev_add,
+    },
+
+STEXI
+@item chardev_add args
+@findex chardev_add
+
+chardev_add accepts the same parameters as the -chardev command line switch.
+
+ETEXI
+
+    {
+        .name       = "chardev-remove",
+        .args_type  = "id:s",
+        .params     = "id",
+        .help       = "remove chardev",
+        .mhandler.cmd = hmp_chardev_remove,
+    },
+
+STEXI
+@item chardev_remove id
+@findex chardev_remove
+
+Removes the chardev @var{id}.
+
+ETEXI
 
     {
         .name       = "info",