Begin a custom list of errnos for atmel-samd

The uerrno module was written to allow boards to customize the list of
errnos they can raise.  Start by copying the default list.

ports/atmel-samd/mpconfigport.h

@@ -290,6 +290,30 @@ extern const struct _mp_obj_module_t usb_hid_module;
     { MP_OBJ_NEW_QSTR(MP_QSTR_uheap),(mp_obj_t)&uheap_module }, \
     { MP_OBJ_NEW_QSTR(MP_QSTR_ustack),(mp_obj_t)&ustack_module }
 
+#define MICROPY_PY_UERRNO_LIST \
+    X(EPERM) \
+    X(ENOENT) \
+    X(EIO) \
+    X(EBADF) \
+    X(EAGAIN) \
+    X(ENOMEM) \
+    X(EACCES) \
+    X(EEXIST) \
+    X(ENODEV) \
+    X(EISDIR) \
+    X(EINVAL) \
+    X(EOPNOTSUPP) \
+    X(EADDRINUSE) \
+    X(ECONNABORTED) \
+    X(ECONNRESET) \
+    X(ENOBUFS) \
+    X(ENOTCONN) \
+    X(ETIMEDOUT) \
+    X(ECONNREFUSED) \
+    X(EHOSTUNREACH) \
+    X(EALREADY) \
+    X(EINPROGRESS) \
+
 // We need to provide a declaration/definition of alloca()
 #include <alloca.h>