PCI: endpoint: Rename core_init() callback in 'struct pci_epc_event_ops' to epc_init()

PCI: endpoint: Rename core_init() callback in 'struct pci_epc_event_ops' to epc_init()

core_init() callback is used to notify the EPC initialization event to the
EPF drivers. The 'core' prefix was used indicate that the controller IP
core has completed initialization. But it serves no purpose as the EPF
driver will only care about the EPC initialization as a whole and there is
no real benefit to distinguish the IP core part.

Rename the core_init() callback in 'struct pci_epc_event_ops' to epc_init()
to make it more clear.

Link: https://lore.kernel.org/linux-pci/20240430-pci-epf-rework-v4-2-22832d0d456f@linaro.org
Tested-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>