py/mpconfig: Add MICROPY_PY_PLATFORM, enabled at extra features level.

Previously this was explicitly enabled on esp32/stm32/renesas/mimxrt/samd,
but didn't get a default feature level because it wasn't in py/mpconfig.h.

With this commit it's now enabled at the "extra features" level, which adds
rp2, unix-standard, windows, esp8266, webassembly, and some nrf boards.

This work was funded through GitHub Sponsors.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
diff --git a/py/mpconfig.h b/py/mpconfig.h
index e6f1531..c617f57 100644
--- a/py/mpconfig.h
+++ b/py/mpconfig.h
@@ -1726,6 +1726,11 @@
 #define MICROPY_PY_ONEWIRE (0)
 #endif
 
+// Whether to provide the "platform" module
+#ifndef MICROPY_PY_PLATFORM
+#define MICROPY_PY_PLATFORM (MICROPY_CONFIG_ROM_LEVEL_AT_LEAST_EXTRA_FEATURES)
+#endif
+
 /*****************************************************************************/
 /* Hooks for a port to add builtins                                          */