PCI: endpoint: Skip odd BAR when skipping 64bit BAR

Always skip odd BAR when skipping 64bit BARs in pci_epf_test_set_bar()
and pci_epf_test_alloc_space() otherwise pci_epf_test_set_bar() will
call pci_epc_set_bar() on an odd loop index when skipping reserved 64bit
BAR.

Moreover, pci_epf_test_alloc_space() will call pci_epf_alloc_space() on
bind for an odd loop index when BAR is 64bit but leaks on subsequent
unbind by not calling pci_epf_free_space().

Signed-off-by: Alan Mikhak <alan.mikhak@sifive.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com>