kernel: 5.10: silence bogus "Missing #address-cells in interrupt provider" warnings

Rosen reported strange dtc warnings that had their origin in
an upstream patch to 5.8-rc1. Upon further digging this
revealed an ongoing thread [0] discussing the topic:

> [...]I don't think we need a bunch of warning fix patches to add
> these everywhere. Also, the need for #address-cells pretty much makes
> no sense on any modern system. It is a relic from days when the bus
> (address) topology and interrupt topology were related.

and later on:
> So really, we only need to be checking for #address-cells in nodes
> with interrupt-map.

This patch backports just the patch which removed the warning message
(this is from the upstream dtc project [1] - but not the kernel).
the patch does not add the checking of the #address-cells in nodes
with interrupt-map.

[0] <https://lore.kernel.org/linux-devicetree/91e3405245c89f134676449cf3822285798d2ed2.1612189652.git.michal.simek@xilinx.com/>
[1] <https://git.kernel.org/pub/scm/utils/dtc/dtc.git/commit/?id=d8d1a9a77863a8c7031ae82a1d461aa78eb72a7b>
Link: <https://github.com/openwrt/openwrt/pull/4685>
Reported-by: Rosen Penev <rosenp@gmail.com>
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>

target/linux/generic/pending-5.10/050-dtc-checks-Drop-interrupt-provider-address-cells-check.patch

@@ -0,0 +1,28 @@
+From d8d1a9a77863a8c7031ae82a1d461aa78eb72a7b Mon Sep 17 00:00:00 2001
+From: Rob Herring <robh@kernel.org>
+Date: Mon, 11 Oct 2021 14:12:43 -0500
+Subject: [PATCH] checks: Drop interrupt provider '#address-cells' check
+
+'#address-cells' is only needed when parsing 'interrupt-map' properties, so
+remove it from the common interrupt-provider test.
+
+Cc: Andre Przywara <andre.przywara@arm.com>
+Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
+Signed-off-by: Rob Herring <robh@kernel.org>
+Message-Id: <20211011191245.1009682-3-robh@kernel.org>
+Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
+---
+--- a/scripts/dtc/checks.c
++++ b/scripts/dtc/checks.c
+@@ -1569,11 +1569,6 @@ static void check_interrupt_provider(str
+ 	if (!prop)
+ 		FAIL(c, dti, node,
+ 		     "Missing #interrupt-cells in interrupt provider");
+-
+-	prop = get_property(node, "#address-cells");
+-	if (!prop)
+-		FAIL(c, dti, node,
+-		     "Missing #address-cells in interrupt provider");
+ }
+ WARNING(interrupt_provider, check_interrupt_provider, NULL);
+