selftests/bpf: Add missed ima_setup.sh in Makefile

When build bpf test and install it to another folder, e.g.

  make -j10 install -C tools/testing/selftests/ TARGETS="bpf" \
	SKIP_TARGETS="" INSTALL_PATH=/tmp/kselftests

The ima_setup.sh is missed in target folder, which makes test_ima failed.

Fix it by adding ima_setup.sh to TEST_PROGS_EXTENDED.

Fixes: 34b82d3a ("bpf: Add a selftest for bpf_ima_inode_hash")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220516040020.653291-1-liuhangbin@gmail.com