unix: Enable MICROPY_PY_REVERSE_SPECIAL_METHODS.

With inplace methods now disabled by default, it makes sense to enable
reverse methods, as they allow for more useful features, e.g. allow
for datetime module to implement both 2 * HOUR and HOUR * 2 (where
HOUR is e.g. timedelta object).

ports/unix/mpconfigport.h

@@ -85,6 +85,7 @@
 #define MICROPY_PY_BUILTINS_POW3    (1)
 #define MICROPY_PY_MICROPYTHON_MEM_INFO (1)
 #define MICROPY_PY_ALL_SPECIAL_METHODS (1)
+#define MICROPY_PY_REVERSE_SPECIAL_METHODS (1)
 #define MICROPY_PY_ARRAY_SLICE_ASSIGN (1)
 #define MICROPY_PY_BUILTINS_SLICE_ATTRS (1)
 #define MICROPY_PY_SYS_EXIT         (1)