dm: fix probing of all devices that have u-boot, dm-pre-reloc in SPL/TPL

Currently, dm_probe_devices checks that the flags of the device contains
DM_FLAG_PRE_RELOC. However DM_FLAG_PRE_RELOC is a driver - and not a
device - flag. This means that the check in pre_reloc_only mode would
always fail.

Instead, what was aimed to be checked is that either the driver of the
device has the flag set, or that the device has the u-boot,dm-pre-reloc
Device Tree property set.

So let's fix the check to allow u-boot,dm-pre-reloc devices to be
probed.

Cc: Quentin Schulz <foss+uboot@0leil.net>
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
diff --git a/drivers/core/root.c b/drivers/core/root.c
index f24ddfa..c4fb485 100644
--- a/drivers/core/root.c
+++ b/drivers/core/root.c
@@ -363,20 +363,22 @@
 
 static int dm_probe_devices(struct udevice *dev, bool pre_reloc_only)
 {
-	u32 mask = DM_FLAG_PROBE_AFTER_BIND;
-	u32 flags = dev_get_flags(dev);
+	ofnode node = dev_ofnode(dev);
 	struct udevice *child;
 	int ret;
 
-	if (pre_reloc_only)
-		mask |= DM_FLAG_PRE_RELOC;
+	if (pre_reloc_only &&
+	    (!ofnode_valid(node) || !ofnode_pre_reloc(node)) &&
+	    !(dev->driver->flags & DM_FLAG_PRE_RELOC))
+		goto probe_children;
 
-	if ((flags & mask) == mask) {
+	if (dev_get_flags(dev) & DM_FLAG_PROBE_AFTER_BIND) {
 		ret = device_probe(dev);
 		if (ret)
 			return ret;
 	}
 
+probe_children:
 	list_for_each_entry(child, &dev->child_head, sibling_node)
 		dm_probe_devices(child, pre_reloc_only);