MFC 261524,261526,261527:
- Properly set the alignment flags when allocating the initial range for a
BAR. This only really matters when pci_do_realloc_bars is enabled and
the initial allocation of a specific range fails.
- Simplify pci_reserve_map() by calling resource_list_reserve() to allocate
the resource after creating a resource list entry rather than reimplementing
it by hand.
- Add two tunables to ignore certain firmware-assigned resources. These
are mostly useful for debugging.
- hw.pci.clear_bars ignores all firmware-assigned ranges for BARs when
set.
- hw.pci.clear_pcib ignores all firmware-assigned ranges for PCI-PCI
bridge I/O windows when set.