kselftests: depend on elfutils (libelf.h)
kselftests: depend on elfutils (libelf.h)

A lot of failures in BPF selftests are due to a missing
libelf.h, which is needed to construct libbpf.

Signed-off-by: Daniel Díaz <81c1e6f46dfb75ebff90afb11720614d43e597b3@linaro.org>

mrchapp/meta-96boards,kraj/meta-96boards,kraj/meta-96boards,96boards/meta-96boards