doc: release-notes-3.7: Add MSPI API release notes

Add description for all the good work done to add the new MSPI API.

(cherry picked from commit 86da7c3)

Original-Signed-off-by: Swift Tian <swift.tian@ambiq.com>
GitOrigin-RevId: 86da7c3
Change-Id: I60f426a2baa254b9a8ab260029a6cc6c14da39d3
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/zephyr/+/5720754
Tested-by: ChromeOS Prod (Robot) <chromeos-ci-prod@chromeos-bot.iam.gserviceaccount.com>
Commit-Queue: Keith Short <keithshort@chromium.org>
Tested-by: Keith Short <keithshort@chromium.org>
Reviewed-by: Keith Short <keithshort@chromium.org>

doc/releases/release-notes-3.7.rst

@@ -908,6 +908,22 @@ Drivers and Sensors
   * Added release API
   * Added support for mode selection via the device tree
 
+* MSPI
+
+  * Add the new experimental :ref:`MSPI(Multi-bit SPI) <mspi_api>` API, enabling support for
+    advanced SPI controllers and peripherals that typically require command, address and data
+    phases as well as variable latency for a transfer. The API now supports from single wire
+    SDR up to hex wires DDR communication in sync/async ways.
+  * Added MSPI bus emulator under bus emulators to showcase the implementation of the MSPI API.
+  * Added MSPI flash device emulator to showcase the use of the MSPI API and interfacing with
+    MSPI bus controllers.
+  * Added APS6404L QPI pSRAM device driver.
+  * Added ATXP032 OPI NOR flash device driver.
+  * Added Ambiq Apollo3p MSPI controller driver.
+  * Added :zephyr:code-sample:`mspi-async` and :zephyr:code-sample:`mspi-flash` samples to
+    showcase the use of MSPI device drivers.
+  * Added mspi/api and mspi/flash testcase for developers to check their implementations.
+
 * Pin control
 
   * Added driver for Renesas RA8 series