media: cec-ioc-adap-g-caps.rst: document available_log_addrs

The CEC_ADAP_G_CAPS documentation of the cec_caps struct was missing
the available_log_addrs field. Add this.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Documentation/userspace-api/media/cec/cec-ioc-adap-g-caps.rst

@@ -57,6 +57,9 @@ returns the information to the application. The ioctl never fails.
       - ``name[32]``
       - The name of this CEC adapter. The combination ``driver`` and
 	``name`` must be unique.
+    * - __u32
+      - ``available_log_addrs``
+      - The maximum number of logical addresses that can be configured.
     * - __u32
       - ``capabilities``
       - The capabilities of the CEC adapter, see