[Buildroot] [git commit branch/2022.02.x] package/qpdf: link with -latomic if needed

[Peter Korsgaard]

commit: https://git.buildroot.net/buildroot/commit/?id=d6cc9524a44e98f935ae7184a5d21da96f57ba57
branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/2022.02.x

Link with -latomic if needed to avoid the following build failure since
bump to version 10.5.0 in commit
b5352c2177011ca389cbb7c68e78447549cbdaaa and
https://github.com/qpdf/qpdf/commit/c5c1a028cdd3cf345046c46963fb0fdacfb2c33c:

/nvmedata/autobuild/instance-20/output-1/host/lib/gcc/sparc-buildroot-linux-uclibc/10.3.0/../../../../sparc-buildroot-linux-uclibc/bin/ld: /nvmedata/autobuild/instance-20/output-1/build/qpdf-10.5.0/libqpdf/build/.libs/libqpdf.a(QPDF.o): in function `QPDF::QPDF()':
QPDF.cc:(.text+0x4e44): undefined reference to `__atomic_fetch_add_8'

Fixes:
  - http://autobuild.buildroot.org/results/b69e6e380c47bc64c6555899c2f61f57bdae7ecc

Signed-off-by: Fabrice Fontaine <fontaine.fabrice at gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout at mind.be>
(cherry picked from commit 25f56c5d602903b2c572fd05ded3be8bee79f981)
Signed-off-by: Peter Korsgaard <peter at korsgaard.com>
---
 package/qpdf/qpdf.mk | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/package/qpdf/qpdf.mk b/package/qpdf/qpdf.mk
index 8e0769059d..a58781f4f1 100644
--- a/package/qpdf/qpdf.mk
+++ b/package/qpdf/qpdf.mk
@@ -32,4 +32,8 @@ else
 QPDF_CONF_OPTS += --disable-crypto-openssl
 endif
 
+ifeq ($(BR2_TOOLCHAIN_HAS_LIBATOMIC),y)
+QPDF_CONF_ENV += LIBS=-latomic
+endif
+
 $(eval $(autotools-package))