kernel: work_q: Add an init function

k_work_queue_start receives a struct that is expected to be
uninitialized (zeroed). Otherwise the behavior is undefined.

Following the Zephyr semantics, this pr introduce a new init function
for this struct.

Fixes #36865

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>

include/kernel.h

diff --git a/include/kernel.h b/include/kernel.h
index a4dca2b..ec03796 100644
--- a/include/kernel.h
+++ b/include/kernel.h
@@ -3045,6 +3045,17 @@
  */
 bool k_work_cancel_sync(struct k_work *work, struct k_work_sync *sync);
 
+/** @brief Initialize a work queue structure.
+ *
+ * This must be invoked before starting a work queue structure for the first time.
+ * It need not be invoked again on the same work queue structure.
+ *
+ * @funcprops \isr_ok
+ *
+ * @param queue the queue structure to be initialized.
+ */
+void k_work_queue_init(struct k_work_q *queue);
+
 /** @brief Initialize a work queue.
  *
  * This configures the work queue thread and starts it running.  The function