zephyr/moduos: Convert module to use extmod version.

This also adds uos.unlink(), for all ports that use extmod/moduos.c.

Signed-off-by: Damien George <damien@micropython.org>
diff --git a/ports/esp32/mpconfigport.h b/ports/esp32/mpconfigport.h
index e06ee94..ffc1553 100644
--- a/ports/esp32/mpconfigport.h
+++ b/ports/esp32/mpconfigport.h
@@ -75,6 +75,7 @@
 #define MICROPY_PY_UOS_INCLUDEFILE          "ports/esp32/moduos.c"
 #define MICROPY_PY_OS_DUPTERM               (1)
 #define MICROPY_PY_UOS_DUPTERM_NOTIFY       (1)
+#define MICROPY_PY_UOS_UNAME                (1)
 #define MICROPY_PY_UOS_URANDOM              (1)
 #define MICROPY_PY_MACHINE                  (1)
 #define MICROPY_PY_MACHINE_PIN_MAKE_NEW     mp_pin_make_new