Only check to see if a memory resource is a PCI ROM BAR when activating
and deactivating PCI resources. Previously, if a device had more than
48 MSI interrupts, then activating message 48 (which has a rid == PCIR_BIOS)
would incorrectly try to enable the PCI ROM BAR.

Tested by: Olivier Cinquin ocinquin uci edu
MFC after: 3 days