rp2: Add new port to Raspberry Pi RP2 microcontroller.

This commit adds a new port "rp2" which targets the new Raspberry Pi RP2040
microcontroller.

The build system uses pure cmake (with a small Makefile wrapper for
convenience).  The USB driver is TinyUSB, and there is a machine module
with most of the standard classes implemented.  Some examples are provided
in the examples/rp2/ directory.

Work done in collaboration with Graham Sanderson.

Signed-off-by: Damien George <damien@micropython.org>

ports/rp2/modrp2.c

@@ -0,0 +1,41 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020-2021 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "py/runtime.h"
+#include "modrp2.h"
+
+STATIC const mp_rom_map_elem_t rp2_module_globals_table[] = {
+    { MP_ROM_QSTR(MP_QSTR___name__),            MP_ROM_QSTR(MP_QSTR_rp2) },
+    { MP_ROM_QSTR(MP_QSTR_Flash),               MP_ROM_PTR(&rp2_flash_type) },
+    { MP_ROM_QSTR(MP_QSTR_PIO),                 MP_ROM_PTR(&rp2_pio_type) },
+    { MP_ROM_QSTR(MP_QSTR_StateMachine),        MP_ROM_PTR(&rp2_state_machine_type) },
+};
+STATIC MP_DEFINE_CONST_DICT(rp2_module_globals, rp2_module_globals_table);
+
+const mp_obj_module_t mp_module_rp2 = {
+    .base = { &mp_type_module },
+    .globals = (mp_obj_dict_t *)&rp2_module_globals,
+};