doc: release-notes-3.6: add SD and SDHC changes

Add SD and SDHC release notes, including the addition of the SDIO
subsystem

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

Author: danieldegrasse

doc/releases/release-notes-3.6.rst

@@ -520,6 +520,10 @@ Drivers and Sensors
 
 * SDHC
 
+  * Added SDHC driver for Cadence SDHC IP
+  * Added SDHC driver for Infineon CAT1 IP
+  * Added support for SDIO commands to iMX USDHC SDHC driver
+
 * Sensor
 
   * Fixed arithmetic overflow in the LTRF216A driver.
@@ -1062,6 +1066,10 @@ Libraries / Subsystems
   * Fixed issue whereby :kconfig:option:`CONFIG_RETENTION_BUFFER_SIZE` values over 256 would cause
     an infinite loop due to use of 8-bit variables.
 
+* SD
+
+  * Added support for SDIO devices
+
 * Storage
 
   * File systems: LittleFS module has been updated to version 2.8.1.