All callers pass 0 as offset. Therefore remove the parameter and use a
fixed offset 0 in pci_vpd_find_tag().

Link: https://lore.kernel.org/r/f62e6e19-5423-2ead-b2bd-62844b23ef8f@gmail.comSigned-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>