PCI: Update BAR # and window messages

The PCI log messages print the register offsets at some places and BAR
numbers at other places. There is no uniformity in this logging mechanism.
It would be better to print names than register offsets.

Add a helper function that aids in printing more meaningful information
about the BAR numbers like "VF BAR", "ROM", "bridge window", etc.  This
function can be called while printing PCI log messages.

[bhelgaas: fold in Lukas' static array suggestion from
https://lore.kernel.org/all/20211106115831.GA7452@wunner.de/]
Link: https://lore.kernel.org/r/20211106112606.192563-2-puranjay12@gmail.com


Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>