selftests/bpf: Enable cpu v4 tests for RV64

Enable cpu v4 tests for RV64, and the relevant tests have passed.

Signed-off-by: Pu Lehui <pulehui@huawei.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Björn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/r/20230824095001.3408573-8-pulehui@huaweicloud.com


Signed-off-by: Alexei Starovoitov <ast@kernel.org>