PCI: endpoint: Refactor pci_epf_alloc_space() API

Refactor pci_epf_alloc_space() API to accept "epc_features" as a parameter.
This is a preparatory work to make the API more robust.

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Link: https://lore.kernel.org/r/20240207213922.1796533-2-cassel@kernel.org


[mani: reworded commit message]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>