dm: pci: Disable PCI compatibility functions by default

We eventually need to drop the compatibility functions for driver model. As
a first step, create a configuration option to enable them and hide them
when the option is disabled.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index c4e1be3..fb1b09f 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -49,6 +49,7 @@
 CONFIG_SPI_FLASH_WINBOND=y
 CONFIG_DM_ETH=y
 CONFIG_DM_PCI=y
+CONFIG_DM_PCI_COMPAT=y
 CONFIG_PCI_SANDBOX=y
 CONFIG_PINCTRL=y
 CONFIG_PINCONF=y