trinity: needs __sync_val_compare_and_swap_4
syscalls/futex.c uses sync_val_compare_and_swap(). So add dependency on
BR2_TOOLCHAIN_HAS_SYNC_4.
Fixes:
http://autobuild.buildroot.net/results/17f/17f7fe79242a40ff3e588748230de7bf2a010941
Signed-off-by: Rahul Bedarkar <rahulbedarkar89@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>