drivers/pci/Kconfig: Add PCI

Add 'PCI' as a menu option and migrate all existing users.

Signed-off-by: Tom Rini <trini@konsulko.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
diff --git a/configs/mpc5121ads_rev2_defconfig b/configs/mpc5121ads_rev2_defconfig
index 6f60801..1bd7b5c 100644
--- a/configs/mpc5121ads_rev2_defconfig
+++ b/configs/mpc5121ads_rev2_defconfig
@@ -14,6 +14,7 @@
 CONFIG_CMD_PING=y
 CONFIG_CMD_EXT2=y
 CONFIG_CMD_FAT=y
+# CONFIG_PCI is not set
 CONFIG_USB=y
 CONFIG_USB_STORAGE=y
 CONFIG_OF_LIBFDT=y