RISC-V (BPF) Docker kselftest builder/runner

0. Build container (once)

docker build . -t bpf-ci

1. Enter Linux root

# e.g.
cd src/linux

2. Run tests

docker run -it --volume $PWD:/build/my-linux \
               --volume /path/to/docker_ccache:/build/ccache \
			   bpf-ci bash -l run.sh self-bpf-all

Valid test strings

        "self-all") # excluding bpf and net
        "self-net")
        "self-bpf-all") # all bpf tests
        "self-bpf-test_progs")
        "self-bpf-test_progs_no_alu32")
        "self-bpf-test_progs_cpuv4")
        "self-bpf-test_maps")
        "self-bpf-test_verifier")