alif: Add initial port to Alif Ensemble MCUs.

This commit adds the beginning of a new alif port with support for Alif
Ensemble MCUs.  See https://alifsemi.com/

Supported features of this port added by this commit:
- UART REPL.
- TinyUSB support, for REPL and MSC.
- Octal SPI flash support, for filesystem.
- machine.Pin support.

General notes about the port:
- It uses make, similar to other bare-metal ports here.
- The toolchain is the standard arm-none-eabi- toolchain.
- Flashing a board can be done using either the built-in serial bootloader,
  or JLink (both supported here).
- There are two required submodules (one for drivers/SDK, one for security
  tools), both of which are open source and on GitHub.
- No special hardware or software is needed for development, just a board
  connected over USB.

OpenMV have generously sponsored the development of this port.

Signed-off-by: Damien George <damien@micropython.org>
Signed-off-by: iabdalkader <i.abdalkader@gmail.com>

ports/alif/pendsv.h

@@ -0,0 +1,48 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2024 OpenMV LLC.
+ *
+ * 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.
+ */
+#ifndef MICROPY_INCLUDED_ALIF_PENDSV_H
+#define MICROPY_INCLUDED_ALIF_PENDSV_H
+
+#include "py/mpconfig.h"
+
+#ifndef MICROPY_BOARD_PENDSV_ENTRIES
+#define MICROPY_BOARD_PENDSV_ENTRIES
+#endif
+
+enum {
+    PENDSV_DISPATCH_SOFT_TIMER,
+    MICROPY_BOARD_PENDSV_ENTRIES
+    PENDSV_DISPATCH_MAX
+};
+
+#define PENDSV_DISPATCH_NUM_SLOTS PENDSV_DISPATCH_MAX
+
+typedef void (*pendsv_dispatch_t)(void);
+
+void pendsv_init(void);
+void pendsv_schedule_dispatch(size_t slot, pendsv_dispatch_t f);
+
+#endif // MICROPY_INCLUDED_ALIF_PENDSV_H