package/libjxl: fix riscv build

libjxl was failing to build for riscv targets, since commit ff7c37e57
"package/libjxl: security bump to version 0.8.1". Build was failing with
output:

    /build/libjxl-0.8.1/lib/jxl/enc_xyb.cc: In function 'jxl::Image3F jxl::N_SCALAR::TransformToLinearRGB(const jxl::Image3F&, const jxl::ColorEncoding&, float, const JxlCmsInterface&, jxl::ThreadPool*)':
    /build/libjxl-0.8.1/lib/jxl/enc_xyb.cc:223:21: error: variable 'std::atomic<bool> ok' has initializer but incomplete type
      223 |   std::atomic<bool> ok{true};
          |                     ^~

This build failure was due to a missing <atomic> header inclusion. For
some reason, the build failure was observed only with RISC-V toolchains.

This commit fixes the issue by adding an upstream commit, not yet in a
package release. See [1].

Fixes:
http://autobuild.buildroot.org/results/121/12107bc7aea7afae1d2fb935d31b44eee6ea1501

[1] https://github.com/libjxl/libjxl/commit/22d12d74e7bc56b09cfb1973aa89ec8d714fa3fc

Signed-off-by: Julien Olivain <ju.o@free.fr>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit de45aea47bfaffaa3ccef02b247f94ab78ab1add)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libjxl/0002-Add-missing-atomic-content-to-fix-gcc-compilation-fo.patch

@@ -0,0 +1,47 @@
+From 42e944a471672dae8522fbcf161941895ba16632 Mon Sep 17 00:00:00 2001
+From: Eastdong <31920925+IEAST@users.noreply.github.com>
+Date: Thu, 23 Feb 2023 06:08:36 +0800
+Subject: [PATCH] Add missing <atomic> content to fix gcc compilation for RISCV
+ architecture. (#2211)
+
+* Add missing <atomic> content to fix gcc compilation for RISCV architecture.
+
+* add name to AUTHORS
+
+* lint fix
+
+Co-authored-by: Moritz Firsching <firsching@google.com>
+Upstream: https://github.com/libjxl/libjxl/commit/22d12d74e7bc56b09cfb1973aa89ec8d714fa3fc
+Signed-off-by: Julien Olivain <ju.o@free.fr>
+---
+ AUTHORS            | 1 +
+ lib/jxl/enc_xyb.cc | 1 +
+ 2 files changed, 2 insertions(+)
+
+diff --git a/AUTHORS b/AUTHORS
+index 44dcc409..3340422d 100644
+--- a/AUTHORS
++++ b/AUTHORS
+@@ -30,6 +30,7 @@ Daniel Novomeský <dnovomesky@gmail.com>
+ David Burnett <vargolsoft@gmail.com>
+ Dirk Lemstra <dirk@lemstra.org>
+ Don Olmstead <don.j.olmstead@gmail.com>
++Dong Xu <xdong181@gmail.com>
+ Even Rouault <even.rouault@spatialys.com>
+ Fred Brennan <copypaste@kittens.ph>
+ Heiko Becker <heirecka@exherbo.org>
+diff --git a/lib/jxl/enc_xyb.cc b/lib/jxl/enc_xyb.cc
+index c7310765..2fd5d025 100644
+--- a/lib/jxl/enc_xyb.cc
++++ b/lib/jxl/enc_xyb.cc
+@@ -6,6 +6,7 @@
+ #include "lib/jxl/enc_xyb.h"
+ 
+ #include <algorithm>
++#include <atomic>
+ #include <cstdlib>
+ 
+ #undef HWY_TARGET_INCLUDE
+-- 
+2.41.0
+