package/elfutils: link with libatomic if needed

Fix build of elfutils 0.181 with Bootlin SPARC uclibc toolchain added
with commit 1348c569d0cb7f67eca30f170b782aa8b51cc259

Fixes:
 - http://autobuild.buildroot.org/results/31ce9e3861c6229a7869a15d322f5d2f5bfc6165

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit 51b5df23b2019eb9da1fc2ceb43c518dc79f1378)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/elfutils/elfutils.mk

@@ -43,6 +43,10 @@ ELFUTILS_CONF_ENV += \
 ELFUTILS_LDFLAGS = $(TARGET_LDFLAGS) \
 	$(TARGET_NLS_LIBS)
 
+ifeq ($(BR2_TOOLCHAIN_HAS_LIBATOMIC),y)
+ELFUTILS_LDFLAGS += -latomic
+endif
+
 ifeq ($(BR2_TOOLCHAIN_USES_GLIBC),)
 ELFUTILS_DEPENDENCIES += musl-fts
 ELFUTILS_LDFLAGS += -lfts