doc: Bluetooth: Add ATT section in docs

There was no API reference for the ATT APIs.

Signed-off-by: Herman Berget <herman.berget@nordicsemi.no>

doc/connectivity/bluetooth/api/att.rst

@@ -0,0 +1,9 @@
+.. _bt_att:
+
+Attribute Protocol (ATT)
+########################
+
+API Reference
+*************
+
+.. doxygengroup:: bt_att

doc/connectivity/bluetooth/api/index.rst

@@ -6,6 +6,7 @@ Bluetooth APIs
 .. toctree::
    :maxdepth: 1
 
+   att.rst
    audio.rst
    connection_mgmt.rst
    controller.rst

doc/zephyr.doxyfile.in

@@ -2256,6 +2256,7 @@ PREDEFINED             = __DOXYGEN__ \
                          CONFIG_ARCH_HAS_CUSTOM_BUSY_WAIT \
                          CONFIG_ARCH_HAS_CUSTOM_SWAP_TO_MAIN \
                          CONFIG_BT_BREDR \
+                         CONFIG_BT_EATT \
                          CONFIG_BT_MESH_MODEL_EXTENSIONS \
                          CONFIG_BT_REMOTE_INFO \
                          CONFIG_BT_USER_DATA_LEN_UPDATE \

include/zephyr/bluetooth/att.h

@@ -10,6 +10,13 @@
 #ifndef ZEPHYR_INCLUDE_BLUETOOTH_ATT_H_
 #define ZEPHYR_INCLUDE_BLUETOOTH_ATT_H_
 
+/**
+ * @brief Attribute Protocol (ATT)
+ * @defgroup bt_att Attribute Protocol (ATT)
+ * @ingroup bluetooth
+ * @{
+ */
+
 #include <zephyr/sys/slist.h>
 #include <zephyr/bluetooth/conn.h>
 
@@ -110,4 +117,8 @@ enum bt_att_chan_opt {
 }
 #endif
 
+/**
+ * @}
+ */
+
 #endif /* ZEPHYR_INCLUDE_BLUETOOTH_ATT_H_ */