Documentation: PCI: pci-endpoint: Fix EPF ops list

With commit 5779dd0 ("PCI: endpoint: Use notification chain mechanism
to notify EPC events to EPF") the linkup callback has been removed and
replaced by EPC event notifications.

With commit 256ae47 ("PCI: endpoint: Add pci_epf_ops to expose
function-specific attrs") a new (optional) add_cfs callback was added.
Update documentation accordingly.

Link: https://lore.kernel.org/linux-pci/20240418084924.1724703-1-alexander.stein@ew.tq-group.com
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Author: tq-steina

Documentation/PCI/endpoint/pci-endpoint.rst

@@ -172,8 +172,8 @@ by the PCI endpoint function driver.
 	 * bind: ops to perform when a EPC device has been bound to EPF device
 	 * unbind: ops to perform when a binding has been lost between a EPC
 	   device and EPF device
-	 * linkup: ops to perform when the EPC device has established a
-	   connection with a host system
+	 * add_cfs: optional ops to create function specific configfs
+	   attributes
 
   The PCI Function driver can then register the PCI EPF driver by using
   pci_epf_register_driver().