mb/{kontron,supermicro}: Use pcidev_on_root()

Change-Id: I61b3e5c92830f02d61a108dadde25ff261099e57
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/31051
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tristan Corrick <tristan@corrick.kiwi>
diff --git a/src/mainboard/supermicro/x10slm-f/mainboard.c b/src/mainboard/supermicro/x10slm-f/mainboard.c
index 8d0e3b0..4bd5d15 100644
--- a/src/mainboard/supermicro/x10slm-f/mainboard.c
+++ b/src/mainboard/supermicro/x10slm-f/mainboard.c
@@ -32,7 +32,7 @@
  */
 static void hide_ast2400(void)
 {
-	struct device *dev = dev_find_slot(0, PCI_DEVFN(0x1c, 0));
+	struct device *dev = pcidev_on_root(0x1c, 0);
 	if (!dev)
 		return;