dm: sandbox: pci: Enable PCI for sandbox

Enable PCI options so that sandbox can be used for testing this bus with
driver model.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index a216039..24d71d0 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -10,3 +10,6 @@
 CONFIG_CROS_EC_SANDBOX=y
 CONFIG_CROS_EC_KEYB=y
 CONFIG_CMD_CROS_EC=y
+CONFIG_PCI=y
+CONFIG_DM_PCI=y
+CONFIG_PCI_SANDBOX=y