unix, modtermios: Make it properly configurable; fix spelling mistake.

unix/modtermios.c

@@ -63,7 +63,7 @@ STATIC mp_obj_t mod_termios_tcgetattr(mp_obj_t fd_in) {
             cc->items[i] = MP_OBJ_NEW_SMALL_INT(term.c_cc[i]);
         } else {
             // https://docs.python.org/3/library/termios.html says value is *string*,
-            // but now way unicode chars could be there.
+            // but no way unicode chars could be there.
             cc->items[i] = mp_obj_new_bytes(&term.c_cc[i], 1);
         }
     }

unix/mpconfigport.h

@@ -84,13 +84,18 @@ extern const struct _mp_obj_module_t mp_module_ffi;
 #else
 #define MICROPY_PY_TIME_DEF
 #endif
+#if MICROPY_PY_TERMIOS
+#define MICROPY_PY_TERMIOS_DEF { MP_OBJ_NEW_QSTR(MP_QSTR_termios), (mp_obj_t)&mp_module_termios },
+#else
+#define MICROPY_PY_TERMIOS_DEF
+#endif
 
 #define MICROPY_PORT_BUILTIN_MODULES \
     MICROPY_PY_FFI_DEF \
     MICROPY_PY_TIME_DEF \
     { MP_OBJ_NEW_QSTR(MP_QSTR_microsocket), (mp_obj_t)&mp_module_socket }, \
     { MP_OBJ_NEW_QSTR(MP_QSTR__os), (mp_obj_t)&mp_module_os }, \
-    { MP_OBJ_NEW_QSTR(MP_QSTR_termios), (mp_obj_t)&mp_module_termios }, \
+    MICROPY_PY_TERMIOS_DEF \
 
 // type definitions for the specific machine