bpf: Add bpf_jit_supports_fsession()

bpf: Add bpf_jit_supports_fsession()

The added fsession does not prevent running on those architectures, that
haven't added fsession support.

For example, try to run fsession tests on arm64:

test_fsession_basic:PASS:fsession_test__open_and_load 0 nsec
test_fsession_basic:PASS:fsession_attach 0 nsec
check_result:FAIL:test_run_opts err unexpected error: -14 (errno 14)

In order to prevent such errors, add bpf_jit_supports_fsession() to guard
those architectures.

Fixes: 2d419c44658f ("bpf: add fsession support")
Acked-by: Puranjay Mohan <puranjay@kernel.org>
Tested-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260131144950.16294-2-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>