bhndb(4): Skip disabled cores when performing bridge configuration probing.

On BCM4321 chipsets, both PCI and PCIe cores are included, with one of
the cores potentially left floating.

Since the PCI core appears first in the device table, and the PCI
profiles appear first in the resource configuration tables, this resulted in
incorrectly matching and using the PCI/v1 resource configuration on PCIe
devices, rather than the correct PCIe/v1 profile.

Approved by: adrian (mentor, implicit)