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/v38b_defconfig b/configs/v38b_defconfig
index d22de9e..17c1f7f 100644
--- a/configs/v38b_defconfig
+++ b/configs/v38b_defconfig
@@ -9,5 +9,6 @@
 CONFIG_CMD_MII=y
 CONFIG_CMD_PING=y
 CONFIG_CMD_FAT=y
+# CONFIG_PCI is not set
 CONFIG_USB=y
 CONFIG_USB_STORAGE=y