samd/mpconfigport: Set MICROPY_USE_INTERNAL_ERRNO to 1.

Without this, error codes can be misleading.
Signed-off-by: robert-hh <robert@hammelrath.com>

ports/samd/mpconfigport.h

@@ -56,6 +56,7 @@
 #define MICROPY_PY_BUILTINS_HELP            (1)
 #define MICROPY_PY_BUILTINS_HELP_TEXT       samd_help_text
 #define MICROPY_PY_BUILTINS_HELP_MODULES    (1)
+#define MICROPY_USE_INTERNAL_ERRNO          (1)
 #define MICROPY_ENABLE_SCHEDULER            (1)
 #define MICROPY_SCHEDULER_STATIC_NODES      (1)
 #define MICROPY_HW_ENABLE_USBDEV            (1)