PCI: Add "weak" generic pcibios_enable_device() implementation
PCI: Add "weak" generic pcibios_enable_device() implementation

Many architectures implement pcibios_enable_device() the same way, so
provide a default implementation in the core.

Signed-off-by: Bjorn Helgaas <f10ec01be0c6b54271af5c550cd257810bdf3268@google.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs