allow to config port binding:profile

When using OVS HW offload feature we need to create
neutron port with  --binding-profile '{"capabilities": ["switchdev"]}' [1]
To allow this feature to be tested with Mellanox CI we need a way
to configure the port binding:profile in tempest

[1] - https://review.openstack.org/#/c/504911/

Change-Id: I9b562aaabf960d38f623d88e8b88619edbb70fe8
diff --git a/releasenotes/notes/add-port-profile-config-option-2610b2fa67027960.yaml b/releasenotes/notes/add-port-profile-config-option-2610b2fa67027960.yaml
new file mode 100644
index 0000000..b54ee8b
--- /dev/null
+++ b/releasenotes/notes/add-port-profile-config-option-2610b2fa67027960.yaml
@@ -0,0 +1,11 @@
+---
+prelude: >
+    When using OVS HW offload feature we need to create
+    Neutron port with a certain capability. This is done
+    by creating Neutron port with binding profile. To be
+    able to test this we need profile capability support
+    in Tempest as well.
+features:
+  - A new config option 'port_profile' is added to the section
+    'network' to specify capabilities of the port.
+    By default this is set to {}.