Merge pull request #6657 from nitz/adafruit-magtag-2.9-add-boot0

Adds `BOOT0` (`GPIO0`) as a named pin for MagTag.

Author: tannewt

ports/espressif/boards/adafruit_magtag_2.9_grayscale/pins.c

@@ -37,6 +37,8 @@ STATIC const mp_rom_map_elem_t board_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_BUTTON_D), MP_ROM_PTR(&pin_GPIO11) },
     { MP_ROM_QSTR(MP_QSTR_D11), MP_ROM_PTR(&pin_GPIO11) },
 
+    { MP_ROM_QSTR(MP_QSTR_BOOT0), MP_ROM_PTR(&pin_GPIO0) },
+
     { MP_ROM_QSTR(MP_QSTR_LIGHT), MP_ROM_PTR(&pin_GPIO3) },
     { MP_ROM_QSTR(MP_QSTR_A3), MP_ROM_PTR(&pin_GPIO3) },