Link to baremetal API reference from patch_node
Link to baremetal API reference from patch_node

Add a link in the patch_node docstring to the corresponding baremetal
API operation, Update Node (PATCH /v1/nodes/{node_ident}).

Change-Id: Id13b1d148c7200ce78787181aa3f376372f21df6

stackforge/python-openstacksdk,openstack/python-openstacksdk,openstack/python-openstacksdk,dtroyer/python-openstacksdk,stackforge/python-openstacksdk,dtroyer/python-openstacksdk