PCI/VPD: Remove pci_vpd_find_tag() SRDT handling

Only SRDT tag is the end tag, and no caller is interested in it.  This
allows to remove all SRDT tag handling.

Link: https://lore.kernel.org/r/3f63f06f-734f-8fff-9518-27fe1faf903d@gmail.com


Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>