dm: pci: Move common auto-config functions to a common file

Some functions will be used by driver model and legacy PCI code. To avoid
duplication, put these in a separate, shared file.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index dee844f..1f8f86f 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -13,7 +13,7 @@
 else
 obj-$(CONFIG_PCI) += pci.o
 endif
-obj-$(CONFIG_PCI) += pci_common.o pci_auto_old.o pci_rom.o
+obj-$(CONFIG_PCI) +=  pci_auto_common.o pci_auto_old.o pci_common.o pci_rom.o
 
 obj-$(CONFIG_FSL_PCI_INIT) += fsl_pci_init.o
 obj-$(CONFIG_PCI_INDIRECT_BRIDGE) += pci_indirect.o