powerpc/configs/64s: Select ARCH_WANT_DEFAULT_BPF_JIT

Tell the generic BPF code that the JIT should be enabled by default,
rather than the interpreter. Most distros use CONFIG_BPF_JIT_ALWAYS_ON=y
anyway, so this just updates upstream to more closely match that.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230414132415.821564-7-mpe@ellerman.id.au