mgmt: updatehub: Conversion of k_work API
mgmt: updatehub: Conversion of k_work API

Replace all existing deprecated API with the recommended alternative.

Fixes: #34101

Signed-off-by: Peter Bigot <a4112a160b558d5427af084318038e19a95979ee@nordicsemi.no>
Signed-off-by: Gerson Fernando Budke <de7eb9f159f7e30f8dcdecee89db6e1a285bf5b2@ossystems.com.br>

galak/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr