doc: release-notes-3.3: Document stm32 exti related change

Document changes that were made to STM32 interrupt controller.

Signed-off-by: Erwan Gouriou <[email protected]>

Author: erwango

doc/releases/release-notes-3.3.rst

@@ -181,6 +181,9 @@ Deprecated in this release
   :kconfig:option:`CONFIG_COUNTER_RTC_STM32_CLOCK_LSE` options are now
   deprecated.
 
+* STM32 Interrupt controller Kconfig symbols such as :kconfig:option:`CONFIG_EXTI_STM32_EXTI0_IRQ_PRI`
+  are removed. Related IRQ prioritues should now be configured in device tree.
+
 * File backend for settings APIs and Kconfig options were deprecated:
 
   :c:func:`settings_mount_fs_backend` in favor of :c:func:`settings_mount_file_backend`
@@ -384,6 +387,8 @@ Drivers and Sensors
 
 * Interrupt Controller
 
+  * STM32: Driver configuration and initialization is now based on device tree
+
 * IPM
 
 * KSCAN