selftests/bpf: CONFIG_LIRC required for test_lirc_mode2.sh

test_lirc_mode2.sh assumes presence of /sys/class/rc/rc0/lirc*/uevent
which will not be present unless CONFIG_LIRC=y

Fixes: 6bdd533c ("bpf: add selftest for lirc_mode2 type program")
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/1590147389-26482-3-git-send-email-alan.maguire@oracle.com