ANDROID: arm64: bpf: implement arch_bpf_jit_check_func

Implement arch_bpf_jit_check_func to check that pointers to jited BPF
functions are correctly aligned and point to the BPF JIT region. This
narrows down the attack surface on the stored pointer.

Bug: 140377409
Change-Id: I10c448eda6a8b0bf4c16ee591fc65974696216b9
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
(cherry picked from commit c10baf76)