doc: release-notes/3.2: add bits on PECI drivers

This adds bits about PECI drivers:

* Devicetree binding changes for the ITE it8xxx2 driver.
* New driver for Nuvoton NPCX.

Signed-off-by: Daniel Leung <[email protected]>

Author: dcpleung

doc/releases/release-notes-3.2.rst

@@ -406,6 +406,11 @@ Drivers and Sensors
 
 * PECI
 
+  * Added PECI driver for Nuvoton NPCX family.
+  * Devicetree binding for ITE it8xxx2 PECI driver has changed from
+    ``ite,peci-it8xxx2`` to :dtcompatible:`ite,it8xxx2-peci` so that this aligns
+    with other ITE devices.
+
 * Pinmux
 
 * Pin control