net/nfp: localize mapping of ethdev to PCI device
net/nfp: localize mapping of ethdev to PCI device

This simplifies later changes to ethdev.

Signed-off-by: Jan Blunck <428a1e03bf18d7720952a3563b48222e4a94a135@infradead.org>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk