applications: nrf_desktop: doc: update nRF54H20 DK board configuration

Updated the nRF54H20 DK entry in board configuration documentation of
the nRF Desktop application to align the description with the recent
migration to the IronSide SE architecture.

Ref: NCSDK-35488

Signed-off-by: Kamil Piszczek <[email protected]>

Author: kapi-no

applications/nrf_desktop/board_configuration.rst

@@ -196,11 +196,12 @@ Sample mouse or dongle (``nrf54h20dk/nrf54h20/cpuapp``)
         The :option:`CONFIG_DESKTOP_BLE_ADV_CTRL_ENABLE` and :option:`CONFIG_DESKTOP_BLE_ADV_CTRL_SUSPEND_ON_USB` Kconfig options are enabled in mouse configurations to improve the USB High-Speed report rate.
       * In ``debug`` configurations, logs are provided through the UART.
         For detailed information on working with the nRF54H20 DK, see the :ref:`ug_nrf54h20_gs` documentation.
-      * The configurations use the Software Updates for Internet of Things (SUIT) and support firmware updates using the :ref:`nrf_desktop_dfu`.
+      * The configurations use the MCUboot bootloader built in the direct-xip mode (``MCUBOOT+XIP``) and support firmware updates using the :ref:`nrf_desktop_dfu`.
         Configurations acting as HID peripherals also support firmware updates using the :ref:`nrf_desktop_dfu_mcumgr`.
+        For more details on MCUboot, see :ref:`nrf_desktop_bootloader`.
 
-      .. note::
-         The nRF Desktop application does not build or run for the ``nrf54h20dk/nrf54h20/cpuapp`` board target due to the IronSide SE migration.
-         See the ``NCSDK-34299`` in the :ref:`known_issues` page for more information.
-         The :ref:`nrf_desktop` documentation may still refer to concepts that were valid before the IronSide SE migration (for example, to the SUIT solution).
-         The codebase and documentation will be updated in the future releases to address this issue.
+        All configurations enable hardware cryptography for the MCUboot bootloader.
+        The MCUboot bootloader uses the :ref:`ug_crypto_architecture_implementation_standards_ironside` for hardware cryptography.
+        The application image is verified using a pure ED25519 signature.
+        In all configurations, the MCUboot bootloader uses a merged image slot that combines both application and radio core images.
+        For more details on nRF54H Series DFU, see :ref:`ug_nrf54h20_mcuboot_dfu`.