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/r2dplus_defconfig b/configs/r2dplus_defconfig
index 1c1e304..f4dc68e 100644
--- a/configs/r2dplus_defconfig
+++ b/configs/r2dplus_defconfig
@@ -5,4 +5,5 @@
 CONFIG_CMD_PING=y
 CONFIG_CMD_CACHE=y
 CONFIG_CMD_EXT2=y
+CONFIG_PCI=y
 CONFIG_USE_PRIVATE_LIBGCC=y