py/objnone: Use mp_generic_unary_op instead of custom one.
diff --git a/py/objnone.c b/py/objnone.c
index 74c02e4..5d5b835 100644
--- a/py/objnone.c
+++ b/py/objnone.c
@@ -43,20 +43,11 @@
     }
 }
 
-STATIC mp_obj_t none_unary_op(mp_uint_t op, mp_obj_t o_in) {
-    (void)o_in;
-    switch (op) {
-        // MP_UNARY_OP_BOOL is handled by a fast-path in mp_obj_is_true
-        case MP_UNARY_OP_HASH: return MP_OBJ_NEW_SMALL_INT((mp_uint_t)o_in);
-        default: return MP_OBJ_NULL; // op not supported
-    }
-}
-
 const mp_obj_type_t mp_type_NoneType = {
     { &mp_type_type },
     .name = MP_QSTR_NoneType,
     .print = none_print,
-    .unary_op = none_unary_op,
+    .unary_op = mp_generic_unary_op,
 };
 
 const mp_obj_none_t mp_const_none_obj = {{&mp_type_NoneType}};