drivers: Replace bad uses of `find_resource`

The `find_resource` function will never return null (will die instead).
In cases where the existing code already accounts for null pointers, it
is better to use `probe_resource` instead, which returns a null pointer
instead of dying.

Change-Id: Ia9a4b62c857f7362d67aee4f9de3bb2da1838394
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58908
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
diff --git a/src/drivers/usb/pci_ehci.c b/src/drivers/usb/pci_ehci.c
index d59ca32..8e85426 100644
--- a/src/drivers/usb/pci_ehci.c
+++ b/src/drivers/usb/pci_ehci.c
@@ -75,7 +75,7 @@
 
 	if (ehci_drv_ops->set_resources)
 		ehci_drv_ops->set_resources(dev);
-	res = find_resource(dev, EHCI_BAR_INDEX);
+	res = probe_resource(dev, EHCI_BAR_INDEX);
 	if (!res)
 		return;