link atomic under clang (#1232)
link atomic under clang (#1232)

Fix #1223

Signed-off-by: Dan Rose <2591e5f46f28d303f9dc027d475a5c60d8dea17a@digilabs.io>
eProsima/Fast-RTPS,eProsima/Fast-DDS,eProsima/Fast-DDS,eProsima/Fast-RTPS,eProsima/Fast-RTPS,eProsima/Fast-RTPS,eProsima/Fast-DDS,eProsima/Fast-DDS,eProsima/Fast-RTPS,eProsima/Fast-DDS