PCI: Remove pci_enable_device_bars() from documentation

Patch below removes pci_enable_device_bars() from Documentation/pci.txt .

Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>