package/libdrm: link with libatomic if needed

Fixes:
https://autobuild.buildroot.net/results/ea0/ea085cdea8458768c5f0ddb16f618a572406e65a/

The oldest build error dates back to May 2024
https://autobuild.buildroot.net/results/8ff/8ff4e16bb79294c5e289989855b5875851342909/
so a backport to LTS branches should be considered.

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Arnout Vandecappelle <arnout@rnout.be>

package/libdrm/libdrm.mk

@@ -19,6 +19,8 @@ LIBDRM_CONF_OPTS = \
 	-Dcairo-tests=disabled \
 	-Dman-pages=disabled
 
+LIBDRM_LDFLAGS = $(TARGET_LDFLAGS)
+
 ifeq ($(BR2_PACKAGE_LIBATOMIC_OPS),y)
 LIBDRM_DEPENDENCIES += libatomic_ops
 ifeq ($(BR2_sparc_v8)$(BR2_sparc_leon3),y)
@@ -26,6 +28,11 @@ LIBDRM_CFLAGS = $(TARGET_CFLAGS) -DAO_NO_SPARC_V9
 endif
 endif
 
+# Uses __atomic_fetch_add_4
+ifeq ($(BR2_TOOLCHAIN_HAS_LIBATOMIC),y)
+LIBDRM_LDFLAGS += -latomic
+endif
+
 ifeq ($(BR2_PACKAGE_LIBDRM_INTEL),y)
 LIBDRM_CONF_OPTS += -Dintel=enabled
 LIBDRM_DEPENDENCIES += libpciaccess