bindesc: add to os_services doxygen group

Instead of being a top-level group.

Signed-off-by: Gerard Marull-Paretas <[email protected]>

Author: gmarull

include/zephyr/bindesc.h

@@ -27,6 +27,7 @@ extern "C" {
 /**
  * @brief Binary Descriptor Definition
  * @defgroup bindesc_define Bindesc Define
+ * @ingroup os_services
  * @{
  */