spl: CONFIG_SPL_PCI_PNP should depend on CONFIG_SPL_PCI

CONFIG_SPL_PCI_PNP=y without CONFIG_SPL_PCI=y makes no sense.

Fixes: 32f5e9e5 ("nvme: pci: Enable for SPL")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Tom Rini <trini@konsulko.com>