PCI: Identify Enhanced Allocation (EA) BAR Equivalent resources in sysfs

Resource flags are exposed to userspace via the sysfs "resource" file.
lspci reads the sysfs file to determine resource properties.

Add a "BAR Equivalent Indicator" flag so lspci can distinguish between
[virtual] and [enhanced] resources.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sean O. Stalley <sean.stalley@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>