pci: Add helper to find a VPD resource data type

This patch adds the pci_vpd_find_tag() helper function to find VPD
resource data types in a buffer.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/pci/Makefile

@@ -4,7 +4,7 @@
 
 obj-y		+= access.o bus.o probe.o remove.o pci.o quirks.o \
 			pci-driver.o search.o pci-sysfs.o rom.o setup-res.o \
-			irq.o
+			irq.o vpd.o
 obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_SYSFS) += slot.o