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/mecp5123_defconfig b/configs/mecp5123_defconfig
index 98f0068..903f6f2 100644
--- a/configs/mecp5123_defconfig
+++ b/configs/mecp5123_defconfig
@@ -11,4 +11,5 @@
 CONFIG_CMD_MII=y
 CONFIG_CMD_PING=y
 CONFIG_CMD_FAT=y
+# CONFIG_PCI is not set
 CONFIG_OF_LIBFDT=y