doc: releases: update disk release notes for 3.2

Update release notes with changes to disk subsystem since 3.1 release.

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

Author: danieldegrasse

doc/releases/release-notes-3.2.rst

@@ -266,6 +266,9 @@ Drivers and Sensors
 
 * Disk
 
+  * Added support for DMA transfers when using STM32 SD host controller
+  * Added support for SD host controller present on STM32L5X family
+
 * DMA
 
 * EEPROM