Allow barebox to overlay states

Signed-off-by: Pascal Vizeli <pvizeli@syshack.ch>

buildroot-external/board/rpi2/patches/barebox/0003-common-state-allow-to-overlay-state-backend.patch

@@ -0,0 +1,42 @@
+From 19ab0b433893cc7d16e8f4a6052f0f784131c43a Mon Sep 17 00:00:00 2001
+From: Pascal Vizeli <pvizeli@syshack.ch>
+Date: Sat, 2 Jun 2018 22:08:31 +0000
+Subject: [PATCH 1/1] common: state: allow to overlay state backend
+
+This allow to use overlay for state backends. I.e. on raspberry you need
+use barebox with SDHCI (slow) and after linux boot it will use SDHOST driver.
+But the problem now is, that the state is on SDHCI and dt-utils need it on
+SDHOST. Actual it is not possible to overwrite this.
+
+Signed-off-by: Pascal Vizeli <pvizeli@syshack.ch>
+---
+ common/state/state.c | 13 +++++++++++--
+ 1 file changed, 11 insertions(+), 2 deletions(-)
+
+diff --git a/common/state/state.c b/common/state/state.c
+index 25d950211..e6259043f 100644
+--- a/common/state/state.c
++++ b/common/state/state.c
+@@ -494,8 +494,17 @@ static int of_state_fixup(struct device_node *root, void *ctx)
+ 	}
+ 
+ 	/* backend phandle */
+-	backend_node = of_find_node_by_reproducible_name(root,
+-						state->backend_reproducible_name);
++	if (node) {
++		ret = of_property_read_u32(node, "backend", &phandle);
++		if (ret)
++			goto out;
++
++		backend_node = of_find_node_by_phandle_from(phandle, root);
++	} else {
++		backend_node = of_find_node_by_reproducible_name(root,
++					state->backend_reproducible_name);
++	}
++
+ 	if (!backend_node) {
+ 		ret = -ENODEV;
+ 		goto out;
+-- 
+2.17.0
+