PCI: endpoint: Remove unused devm_pci_epc_destroy()

PCI: endpoint: Remove unused devm_pci_epc_destroy()

The static function devm_pci_epc_match() is only invoked within the
devm_pci_epc_destroy(). However, since it was initially introduced,
this new API has had no callers.

Thus, remove both the unused API and the static function.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20250217-remove_api-v2-1-b169c9117045@quicinc.com
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>