qapi-schema: remove legacy<> from doc

The legacy<> type is no longer used since 7ce7ffe0.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

qapi-schema.json

@@ -1632,13 +1632,10 @@
 #        1) A primitive type such as 'u8', 'u16', 'bool', 'str', or 'double'.
 #           These types are mapped to the appropriate JSON type.
 #
-#        2) A legacy type in the form 'legacy<subtype>' where subtype is the
-#           legacy qdev typename.  These types are always treated as strings.
-#
-#        3) A child type in the form 'child<subtype>' where subtype is a qdev
+#        2) A child type in the form 'child<subtype>' where subtype is a qdev
 #           device type name.  Child properties create the composition tree.
 #
-#        4) A link type in the form 'link<subtype>' where subtype is a qdev
+#        3) A link type in the form 'link<subtype>' where subtype is a qdev
 #           device type name.  Link properties form the device model graph.
 #
 # Since: 1.2
@@ -1689,10 +1686,10 @@
 #
 # @property: The property name to read
 #
-# Returns: The property value.  The type depends on the property type.  legacy<>
-#          properties are returned as #str.  child<> and link<> properties are
-#          returns as #str pathnames.  All integer property types (u8, u16, etc)
-#          are returned as #int.
+# Returns: The property value.  The type depends on the property
+#          type. child<> and link<> properties are returned as #str
+#          pathnames.  All integer property types (u8, u16, etc) are
+#          returned as #int.
 #
 # Since: 1.2
 ##