Announce PCI Segment Groups supported to PCI host _OSC.
According to ACPI 6.3 specification:
The OS sets this bit to 1 if it supports PCI Segment Groups as defined by the _SEG object, and access to the configuration space of devices in PCI Segment Groups as described by this specification. Otherwise, the OS sets this bit to 0.
As far as I see we support both of those as PCI domains for quite a while.
MFC after: 2 months